<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e6595-ff60-7818-bf6b-18e65b9b0a00,g:73612ed2-4fac-4841-9aea-81c8b6d96854-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://oxy.com/role/Cover" xlink:type="simple" xlink:href="oxy-20260629.xsd#Cover"/>
  <link:definitionLink xlink:role="http://oxy.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_019e6599-8623-790e-b216-8cc063db9139" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019e6599-8623-7ada-8205-62546a2c6115" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_019e6599-8623-790e-b216-8cc063db9139" xlink:to="loc_dei_DocumentInformationTable_019e6599-8623-7ada-8205-62546a2c6115" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7b16-916c-182816a5beac" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019e6599-8623-7ada-8205-62546a2c6115" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7b16-916c-182816a5beac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7b16-916c-182816a5beac_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7b16-916c-182816a5beac" xlink:to="loc_dei_EntityDomain_019e6599-8623-7b16-916c-182816a5beac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7931-8811-2b5f26ce83e1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7b16-916c-182816a5beac" xlink:to="loc_dei_EntityDomain_019e6599-8623-7931-8811-2b5f26ce83e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-76f9-88ec-6961dcf0e793" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7931-8811-2b5f26ce83e1" xlink:to="loc_oxy_EBP001Member_019e6599-8623-76f9-88ec-6961dcf0e793" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019e6599-8623-708a-ae40-bbd2fcaebdbc" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019e6599-8623-790e-b216-8cc063db9139" xlink:to="loc_dei_DocumentType_019e6599-8623-708a-ae40-bbd2fcaebdbc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019e6599-8623-7660-b7dc-f0d9f1b1b308" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019e6599-8623-790e-b216-8cc063db9139" xlink:to="loc_dei_EntityRegistrantName_019e6599-8623-7660-b7dc-f0d9f1b1b308" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019e6599-8623-7bbe-bdfa-577c7e2e24e0" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019e6599-8623-790e-b216-8cc063db9139" xlink:to="loc_dei_AmendmentFlag_019e6599-8623-7bbe-bdfa-577c7e2e24e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019e6599-8623-77ec-95e7-c3b1e2cb8bd6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019e6599-8623-790e-b216-8cc063db9139" xlink:to="loc_dei_EntityCentralIndexKey_019e6599-8623-77ec-95e7-c3b1e2cb8bd6" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/StatementsofNetAssetsAvailableforBenefits" xlink:type="simple" xlink:href="oxy-20260629.xsd#StatementsofNetAssetsAvailableforBenefits"/>
  <link:definitionLink xlink:role="http://oxy.com/role/StatementsofNetAssetsAvailableforBenefits" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems_019e65b1-dfa8-7e9a-b9ea-41843d0e4ba6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable_019e65b1-dfa8-7674-8547-fc6544828c4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems_019e65b1-dfa8-7e9a-b9ea-41843d0e4ba6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable_019e65b1-dfa8-7674-8547-fc6544828c4d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e65b1-dfa8-7103-81c4-1e6f62d24d13" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable_019e65b1-dfa8-7674-8547-fc6544828c4d" xlink:to="loc_dei_LegalEntityAxis_019e65b1-dfa8-7103-81c4-1e6f62d24d13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e65b1-dfa8-7103-81c4-1e6f62d24d13_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e65b1-dfa8-7103-81c4-1e6f62d24d13" xlink:to="loc_dei_EntityDomain_019e65b1-dfa8-7103-81c4-1e6f62d24d13_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e65b1-dfa8-796c-99fe-a547dbc397f3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e65b1-dfa8-7103-81c4-1e6f62d24d13" xlink:to="loc_dei_EntityDomain_019e65b1-dfa8-796c-99fe-a547dbc397f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e65b1-dfa8-72d5-8e4a-f4d10d0990b1" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e65b1-dfa8-796c-99fe-a547dbc397f3" xlink:to="loc_oxy_EBP001Member_019e65b1-dfa8-72d5-8e4a-f4d10d0990b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e65bc-cc37-71f4-b071-11f6c55e570f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable_019e65b1-dfa8-7674-8547-fc6544828c4d" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e65bc-cc37-71f4-b071-11f6c55e570f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e65bc-cc37-71f4-b071-11f6c55e570f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e65bc-cc37-71f4-b071-11f6c55e570f" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e65bc-cc37-71f4-b071-11f6c55e570f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e65bc-cc37-7563-bd4e-fc101e8ac7d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e65bc-cc37-71f4-b071-11f6c55e570f" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e65bc-cc37-7563-bd4e-fc101e8ac7d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_019e65c1-26b8-774b-b903-b4cc79f02f1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e65bc-cc37-7563-bd4e-fc101e8ac7d7" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_019e65c1-26b8-774b-b903-b4cc79f02f1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849d-e909-7a63-a65e-d522c50d1615" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e65bc-cc37-7563-bd4e-fc101e8ac7d7" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849d-e909-7a63-a65e-d522c50d1615" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e65b1-dfa8-7b5c-ae06-2f59cf5e0926" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems_019e65b1-dfa8-7e9a-b9ea-41843d0e4ba6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e65b1-dfa8-7b5c-ae06-2f59cf5e0926" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairAndContractValueAbstract_019e65b6-ed43-762e-ae31-a565bb31e8d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairAndContractValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e65b1-dfa8-7b5c-ae06-2f59cf5e0926" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairAndContractValueAbstract_019e65b6-ed43-762e-ae31-a565bb31e8d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e65b1-dfa8-7ef5-8f02-89378625ba65" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairAndContractValueAbstract_019e65b6-ed43-762e-ae31-a565bb31e8d4" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e65b1-dfa8-7ef5-8f02-89378625ba65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue_019e65b4-31f2-732e-9603-015b9ffd2b5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e65b1-dfa8-7ef5-8f02-89378625ba65" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue_019e65b4-31f2-732e-9603-015b9ffd2b5f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustFairValue_019e65b1-dfa8-7149-bf63-32203a8c01ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e65b1-dfa8-7ef5-8f02-89378625ba65" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustFairValue_019e65b1-dfa8-7149-bf63-32203a8c01ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e65b4-4d00-7116-af24-010f502508eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e65b1-dfa8-7ef5-8f02-89378625ba65" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e65b4-4d00-7116-af24-010f502508eb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract_019e65b6-6a49-7a26-8c01-cd0109e3041e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairAndContractValueAbstract_019e65b6-ed43-762e-ae31-a565bb31e8d4" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract_019e65b6-6a49-7a26-8c01-cd0109e3041e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustContractValue_019e65b3-bab5-7e09-8c79-ffccdf3dd22b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustContractValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract_019e65b6-6a49-7a26-8c01-cd0109e3041e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPlanInterestInMasterTrustContractValue_019e65b3-bab5-7e09-8c79-ffccdf3dd22b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e65b1-dfa8-7b5c-ae06-2f59cf5e0926" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant_019e65b1-dfa8-7b55-ab0d-c8c7308d543d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant_019e65b1-dfa8-7b55-ab0d-c8c7308d543d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable_019e65b9-926d-786e-8feb-2f5936775b03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable_019e65b9-926d-786e-8feb-2f5936775b03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantContributionReceivable_019e65b1-dfa8-7020-b671-51da5f2990d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantContributionReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantContributionReceivable_019e65b1-dfa8-7020-b671-51da5f2990d0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable_019e65b1-dfa8-748f-922a-c74b54e84489" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable_019e65b1-dfa8-748f-922a-c74b54e84489" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReceivable_019e65b1-dfa8-7438-9c5d-1447209dd8b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e65b1-dfa8-7ef6-bbd5-54f7eb4f8d34" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReceivable_019e65b1-dfa8-7438-9c5d-1447209dd8b1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAsset_019e65b8-afc2-7c12-ae74-5156bc8d6409" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e65b1-dfa8-7b5c-ae06-2f59cf5e0926" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAsset_019e65b8-afc2-7c12-ae74-5156bc8d6409" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e65b1-dfa8-772a-aca3-9b709e9dcc3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitLineItems_019e65b1-dfa8-7e9a-b9ea-41843d0e4ba6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e65b1-dfa8-772a-aca3-9b709e9dcc3a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/StatementofChangesinNetAssetsAvailableforBenefits" xlink:type="simple" xlink:href="oxy-20260629.xsd#StatementofChangesinNetAssetsAvailableforBenefits"/>
  <link:definitionLink xlink:role="http://oxy.com/role/StatementofChangesinNetAssetsAvailableforBenefits" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems_019e65c3-98ca-7e86-983c-36031fcc6e0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable_019e65c3-98ca-7782-8210-aeeb8e8b5298" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems_019e65c3-98ca-7e86-983c-36031fcc6e0c" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable_019e65c3-98ca-7782-8210-aeeb8e8b5298" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e65c3-98ca-7513-8857-f56761ab6cdf" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable_019e65c3-98ca-7782-8210-aeeb8e8b5298" xlink:to="loc_dei_LegalEntityAxis_019e65c3-98ca-7513-8857-f56761ab6cdf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e65c3-98ca-7513-8857-f56761ab6cdf_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e65c3-98ca-7513-8857-f56761ab6cdf" xlink:to="loc_dei_EntityDomain_019e65c3-98ca-7513-8857-f56761ab6cdf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e65c3-98ca-75f5-9fff-6f1d90fc99f4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e65c3-98ca-7513-8857-f56761ab6cdf" xlink:to="loc_dei_EntityDomain_019e65c3-98ca-75f5-9fff-6f1d90fc99f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e65c3-98ca-78e2-81bd-34cf97e6ccbf" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e65c3-98ca-75f5-9fff-6f1d90fc99f4" xlink:to="loc_oxy_EBP001Member_019e65c3-98ca-78e2-81bd-34cf97e6ccbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems_019e65c3-98ca-7e86-983c-36031fcc6e0c" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment_019e65c4-b089-7e71-b167-6600b58dea41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment_019e65c4-b089-7e71-b167-6600b58dea41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment_019e65c4-bc7c-74ed-8df5-bd8e6c3dbe0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment_019e65c4-bc7c-74ed-8df5-bd8e6c3dbe0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019e65c3-98ca-7f18-9e34-2d484b02c3f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019e65c3-98ca-7f18-9e34-2d484b02c3f5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForChangeInPlanInterestInMasterTrust_019e65c5-8786-766d-aae8-e981116ac5e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForChangeInPlanInterestInMasterTrust"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForChangeInPlanInterestInMasterTrust_019e65c5-8786-766d-aae8-e981116ac5e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment_019e65c3-98ca-7c39-a3c1-abcef1e7e257" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract_019e65c3-98ca-7596-b0b6-c939e8cdee20" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment_019e65c3-98ca-7c39-a3c1-abcef1e7e257" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnNoteReceivableFromParticipant_019e65c3-98ca-78ed-8ded-506333e94fa7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnNoteReceivableFromParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnNoteReceivableFromParticipant_019e65c3-98ca-78ed-8ded-506333e94fa7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract_019e65c3-98ca-7189-b5a4-05e4a94eb921" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract_019e65c3-98ca-7189-b5a4-05e4a94eb921" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover_019e65c3-98ca-78dc-9304-bc788b80e39c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract_019e65c3-98ca-7189-b5a4-05e4a94eb921" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover_019e65c3-98ca-78dc-9304-bc788b80e39c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContributionCash_019e65c3-98ca-7d97-a87e-d2416bae9971" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContributionCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract_019e65c3-98ca-7189-b5a4-05e4a94eb921" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContributionCash_019e65c3-98ca-7d97-a87e-d2416bae9971" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionRollover_019e65c3-98ca-7131-b328-fb09f2f6c64e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionRollover"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract_019e65c3-98ca-7189-b5a4-05e4a94eb921" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionRollover_019e65c3-98ca-7131-b328-fb09f2f6c64e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution_019e65c3-98ca-7d2f-9ab2-bbac94a3c602" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContributionAbstract_019e65c3-98ca-7189-b5a4-05e4a94eb921" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution_019e65c3-98ca-7d2f-9ab2-bbac94a3c602" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_019e65c3-98ca-7611-b77d-0fd2d1034030" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_019e65c3-98ca-7611-b77d-0fd2d1034030" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019e65c3-98ca-71a2-80f0-f7221b1cba50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_019e65c3-98ca-7611-b77d-0fd2d1034030" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019e65c3-98ca-71a2-80f0-f7221b1cba50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense_019e65c3-98ca-7108-8b72-31bd5d86fd0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_019e65c3-98ca-7611-b77d-0fd2d1034030" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense_019e65c3-98ca-7108-8b72-31bd5d86fd0e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease_019e65c3-98ca-7c83-b5e3-d55ecd809a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_019e65c3-98ca-7611-b77d-0fd2d1034030" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease_019e65c3-98ca-7c83-b5e3-d55ecd809a9e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019e65c3-98ca-7122-af15-88c79b3fcaa2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e65c3-98ca-7727-8fb0-667cf6b41e88" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019e65c3-98ca-7122-af15-88c79b3fcaa2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNetAssetAvailableForBenefitAbstract_019e65ca-cdb8-73c2-a75d-38fc17117f2d" xlink:href="oxy-20260629.xsd#oxy_EBPNetAssetAvailableForBenefitAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems_019e65c3-98ca-7e86-983c-36031fcc6e0c" xlink:to="loc_oxy_EBPNetAssetAvailableForBenefitAbstract_019e65ca-cdb8-73c2-a75d-38fc17117f2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e65c3-98ca-7a46-acce-3eccbafee31b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPNetAssetAvailableForBenefitAbstract_019e65ca-cdb8-73c2-a75d-38fc17117f2d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e65c3-98ca-7a46-acce-3eccbafee31b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e65c3-98ca-7ee6-9fb3-d7b9e2e39ac8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/DescriptionofthePlan" xlink:type="simple" xlink:href="oxy-20260629.xsd#DescriptionofthePlan"/>
  <link:definitionLink xlink:role="http://oxy.com/role/DescriptionofthePlan" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7e23-b994-ecc9cd87c541" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-762b-b334-fa9a9fc5f9a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7e23-b994-ecc9cd87c541" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-762b-b334-fa9a9fc5f9a3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7225-bc8d-82cbbda72b92" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-762b-b334-fa9a9fc5f9a3" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7225-bc8d-82cbbda72b92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7225-bc8d-82cbbda72b92_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7225-bc8d-82cbbda72b92" xlink:to="loc_dei_EntityDomain_019e6599-8623-7225-bc8d-82cbbda72b92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-73c4-95f0-00433cddad42" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7225-bc8d-82cbbda72b92" xlink:to="loc_dei_EntityDomain_019e6599-8623-73c4-95f0-00433cddad42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-71e3-8c22-a8cc87532911" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-73c4-95f0-00433cddad42" xlink:to="loc_oxy_EBP001Member_019e6599-8623-71e3-8c22-a8cc87532911" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock_019e6599-8623-7891-bba2-64e3976cddf6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7e23-b994-ecc9cd87c541" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock_019e6599-8623-7891-bba2-64e3976cddf6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/SummaryofSignificantAccountingPolicies" xlink:type="simple" xlink:href="oxy-20260629.xsd#SummaryofSignificantAccountingPolicies"/>
  <link:definitionLink xlink:role="http://oxy.com/role/SummaryofSignificantAccountingPolicies" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-72d5-a131-f38e891636c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019e6599-8623-77f6-ac5f-d58df9f85fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-72d5-a131-f38e891636c3" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019e6599-8623-77f6-ac5f-d58df9f85fb3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7589-880e-350675e58a3e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019e6599-8623-77f6-ac5f-d58df9f85fb3" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7589-880e-350675e58a3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7589-880e-350675e58a3e_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7589-880e-350675e58a3e" xlink:to="loc_dei_EntityDomain_019e6599-8623-7589-880e-350675e58a3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7bc6-b147-60a238fd9417" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7589-880e-350675e58a3e" xlink:to="loc_dei_EntityDomain_019e6599-8623-7bc6-b147-60a238fd9417" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7c4e-8d23-b25fe7cb8624" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7bc6-b147-60a238fd9417" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7c4e-8d23-b25fe7cb8624" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock_019e6599-8623-7a23-9b0a-3f4bbac5a017" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-72d5-a131-f38e891636c3" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock_019e6599-8623-7a23-9b0a-3f4bbac5a017" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/FairValueMeasurements" xlink:type="simple" xlink:href="oxy-20260629.xsd#FairValueMeasurements"/>
  <link:definitionLink xlink:role="http://oxy.com/role/FairValueMeasurements" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e6599-8623-7027-888b-10e089b21f90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e6599-8623-7629-ba82-d58a2a7323e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e6599-8623-7027-888b-10e089b21f90" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e6599-8623-7629-ba82-d58a2a7323e1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-761c-bd5e-9cfe03defd21" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e6599-8623-7629-ba82-d58a2a7323e1" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-761c-bd5e-9cfe03defd21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-761c-bd5e-9cfe03defd21_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-761c-bd5e-9cfe03defd21" xlink:to="loc_dei_EntityDomain_019e6599-8623-761c-bd5e-9cfe03defd21_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7a44-ab20-51b9f01ddb47" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-761c-bd5e-9cfe03defd21" xlink:to="loc_dei_EntityDomain_019e6599-8623-7a44-ab20-51b9f01ddb47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-79cf-8ff2-6880144ba0e2" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7a44-ab20-51b9f01ddb47" xlink:to="loc_oxy_EBP001Member_019e6599-8623-79cf-8ff2-6880144ba0e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTextBlock_019e6599-8623-712d-8b58-964a8ddf08b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e6599-8623-7027-888b-10e089b21f90" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTextBlock_019e6599-8623-712d-8b58-964a8ddf08b3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/GuaranteedInvestmentContractsMasterTrustAccount" xlink:type="simple" xlink:href="oxy-20260629.xsd#GuaranteedInvestmentContractsMasterTrustAccount"/>
  <link:definitionLink xlink:role="http://oxy.com/role/GuaranteedInvestmentContractsMasterTrustAccount" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019e6fea-9b89-7645-b85c-ed66f26bde38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable_019e6fea-9b89-79e0-8d06-e747f76947ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019e6fea-9b89-7645-b85c-ed66f26bde38" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable_019e6fea-9b89-79e0-8d06-e747f76947ee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6fea-9b89-7fa7-8993-ef1acccbc897" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable_019e6fea-9b89-79e0-8d06-e747f76947ee" xlink:to="loc_dei_LegalEntityAxis_019e6fea-9b89-7fa7-8993-ef1acccbc897" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6fea-9b89-7fa7-8993-ef1acccbc897_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6fea-9b89-7fa7-8993-ef1acccbc897" xlink:to="loc_dei_EntityDomain_019e6fea-9b89-7fa7-8993-ef1acccbc897_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6fea-9b89-791c-97b9-f8037272f1b6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6fea-9b89-7fa7-8993-ef1acccbc897" xlink:to="loc_dei_EntityDomain_019e6fea-9b89-791c-97b9-f8037272f1b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6fea-e384-76c3-ab8d-6f5ff2e505dd" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6fea-9b89-791c-97b9-f8037272f1b6" xlink:to="loc_oxy_EBP001Member_019e6fea-e384-76c3-ab8d-6f5ff2e505dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock_019e6fea-9b89-7574-89cf-9c8c99c0bbb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019e6fea-9b89-7645-b85c-ed66f26bde38" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock_019e6fea-9b89-7574-89cf-9c8c99c0bbb1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanInterestinMasterTrustAccounts" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanInterestinMasterTrustAccounts"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanInterestinMasterTrustAccounts" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-779f-bbfd-6b84a956f528" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7c16-a35d-323fb29a770c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-779f-bbfd-6b84a956f528" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7c16-a35d-323fb29a770c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-75b0-92b0-98d97c73b5be" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7c16-a35d-323fb29a770c" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-75b0-92b0-98d97c73b5be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-75b0-92b0-98d97c73b5be_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-75b0-92b0-98d97c73b5be" xlink:to="loc_dei_EntityDomain_019e6599-8623-75b0-92b0-98d97c73b5be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7f72-870e-9a1bfba8d2a3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-75b0-92b0-98d97c73b5be" xlink:to="loc_dei_EntityDomain_019e6599-8623-7f72-870e-9a1bfba8d2a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7f54-8171-24e59b131e83" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7f72-870e-9a1bfba8d2a3" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7f54-8171-24e59b131e83" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTextBlock_019e6599-8623-7142-b5c9-4ba5052684ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-779f-bbfd-6b84a956f528" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTextBlock_019e6599-8623-7142-b5c9-4ba5052684ed" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/RelatedPartyTransactions" xlink:type="simple" xlink:href="oxy-20260629.xsd#RelatedPartyTransactions"/>
  <link:definitionLink xlink:role="http://oxy.com/role/RelatedPartyTransactions" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems_019e6599-8623-74bd-a80f-02d8ad66f99a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_019e6599-8623-7d1a-887c-c98d018f1fe5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems_019e6599-8623-74bd-a80f-02d8ad66f99a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_019e6599-8623-7d1a-887c-c98d018f1fe5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-730e-989e-f3c9ce54ec60" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_019e6599-8623-7d1a-887c-c98d018f1fe5" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-730e-989e-f3c9ce54ec60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-730e-989e-f3c9ce54ec60_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-730e-989e-f3c9ce54ec60" xlink:to="loc_dei_EntityDomain_019e6599-8623-730e-989e-f3c9ce54ec60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-72a3-ba26-65416564104e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-730e-989e-f3c9ce54ec60" xlink:to="loc_dei_EntityDomain_019e6599-8623-72a3-ba26-65416564104e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-726f-9052-869ae31f4c75" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-72a3-ba26-65416564104e" xlink:to="loc_oxy_EBP001Member_019e6599-8623-726f-9052-869ae31f4c75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock_019e6599-8623-7408-a7e6-60d53645bcb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems_019e6599-8623-74bd-a80f-02d8ad66f99a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock_019e6599-8623-7408-a7e6-60d53645bcb8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanTermination" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanTermination"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanTermination" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6639-91e3-7504-a398-f608486efa5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6639-91e3-776e-89a2-628e87c1ab72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6639-91e3-7504-a398-f608486efa5d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6639-91e3-776e-89a2-628e87c1ab72" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6639-91e3-77b2-b0e7-b92924c64835" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6639-91e3-776e-89a2-628e87c1ab72" xlink:to="loc_dei_LegalEntityAxis_019e6639-91e3-77b2-b0e7-b92924c64835" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6639-91e3-77b2-b0e7-b92924c64835_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6639-91e3-77b2-b0e7-b92924c64835" xlink:to="loc_dei_EntityDomain_019e6639-91e3-77b2-b0e7-b92924c64835_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6639-91e3-74e0-86e5-951c67385513" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6639-91e3-77b2-b0e7-b92924c64835" xlink:to="loc_dei_EntityDomain_019e6639-91e3-74e0-86e5-951c67385513" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e663a-0fd3-7b91-a786-b0ac5d978aff" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6639-91e3-74e0-86e5-951c67385513" xlink:to="loc_oxy_EBP001Member_019e663a-0fd3-7b91-a786-b0ac5d978aff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPlanTerminationTextBlock_019e6639-91e3-755c-a22b-7c9f0d76667c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanTerminationTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6639-91e3-7504-a398-f608486efa5d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanPlanTerminationTextBlock_019e6639-91e3-755c-a22b-7c9f0d76667c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/TaxStatus" xlink:type="simple" xlink:href="oxy-20260629.xsd#TaxStatus"/>
  <link:definitionLink xlink:role="http://oxy.com/role/TaxStatus" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems_019e6599-8623-77d7-a972-0d9b4d0ae99b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable_019e6599-8623-7b9d-86f9-f1f33384c625" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems_019e6599-8623-77d7-a972-0d9b4d0ae99b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable_019e6599-8623-7b9d-86f9-f1f33384c625" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7975-85e3-cec1fcfe2026" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable_019e6599-8623-7b9d-86f9-f1f33384c625" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7975-85e3-cec1fcfe2026" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7975-85e3-cec1fcfe2026_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7975-85e3-cec1fcfe2026" xlink:to="loc_dei_EntityDomain_019e6599-8623-7975-85e3-cec1fcfe2026_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-78e7-9c15-ebad54d7f4fc" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7975-85e3-cec1fcfe2026" xlink:to="loc_dei_EntityDomain_019e6599-8623-78e7-9c15-ebad54d7f4fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-724b-b2a6-8917b55163da" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-78e7-9c15-ebad54d7f4fc" xlink:to="loc_oxy_EBP001Member_019e6599-8623-724b-b2a6-8917b55163da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock_019e6599-8623-7963-8bce-d05c8657206e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems_019e6599-8623-77d7-a972-0d9b4d0ae99b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock_019e6599-8623-7963-8bce-d05c8657206e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/RisksandUncertainties" xlink:type="simple" xlink:href="oxy-20260629.xsd#RisksandUncertainties"/>
  <link:definitionLink xlink:role="http://oxy.com/role/RisksandUncertainties" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6599-8623-7f54-8153-a00fc8e1536f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpRiskAndUncertaintyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6599-8623-7fe2-bc5b-3d6a43f77f3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpRiskAndUncertaintyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6599-8623-7f54-8153-a00fc8e1536f" xlink:to="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6599-8623-7fe2-bc5b-3d6a43f77f3c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7cfb-af26-c951c111c5a4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6599-8623-7fe2-bc5b-3d6a43f77f3c" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7cfb-af26-c951c111c5a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7cfb-af26-c951c111c5a4_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7cfb-af26-c951c111c5a4" xlink:to="loc_dei_EntityDomain_019e6599-8623-7cfb-af26-c951c111c5a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7203-a5c0-43a19925055a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7cfb-af26-c951c111c5a4" xlink:to="loc_dei_EntityDomain_019e6599-8623-7203-a5c0-43a19925055a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-764e-a7d7-e3ce2c1dddf6" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7203-a5c0-43a19925055a" xlink:to="loc_oxy_EBP001Member_019e6599-8623-764e-a7d7-e3ce2c1dddf6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRiskAndUncertaintyTextBlock_019e6599-8623-704f-b6f4-9b115d508a24" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRiskAndUncertaintyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6599-8623-7f54-8153-a00fc8e1536f" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanRiskAndUncertaintyTextBlock_019e6599-8623-704f-b6f4-9b115d508a24" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500" xlink:type="simple" xlink:href="oxy-20260629.xsd#ReconciliationoftheFinancialStatementstotheForm5500"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-713e-8052-3cefcde16019" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-72c0-960f-007522b235f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-713e-8052-3cefcde16019" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-72c0-960f-007522b235f8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7534-ad0e-d0370835fdb5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-72c0-960f-007522b235f8" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7534-ad0e-d0370835fdb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7534-ad0e-d0370835fdb5_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7534-ad0e-d0370835fdb5" xlink:to="loc_dei_EntityDomain_019e6599-8623-7534-ad0e-d0370835fdb5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-72c8-96ff-9b8c52e59957" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7534-ad0e-d0370835fdb5" xlink:to="loc_dei_EntityDomain_019e6599-8623-72c8-96ff-9b8c52e59957" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7e67-ba0d-cc48f29fb465" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-72c8-96ff-9b8c52e59957" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7e67-ba0d-cc48f29fb465" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500TextBlock_019e6599-8623-73aa-a6cc-63698b4b6fba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500TextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-713e-8052-3cefcde16019" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500TextBlock_019e6599-8623-73aa-a6cc-63698b4b6fba" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/SubsequentEvents" xlink:type="simple" xlink:href="oxy-20260629.xsd#SubsequentEvents"/>
  <link:definitionLink xlink:role="http://oxy.com/role/SubsequentEvents" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpSubsequentEventLineItems_019e6599-8623-701c-aa82-5c8fbe4a6484" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpSubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpSubsequentEventTable_019e6599-8623-777c-815c-26f46e560e69" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpSubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EbpSubsequentEventLineItems_019e6599-8623-701c-aa82-5c8fbe4a6484" xlink:to="loc_us-gaap-ebp_EbpSubsequentEventTable_019e6599-8623-777c-815c-26f46e560e69" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-70dc-94d8-a2bc6cd83400" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EbpSubsequentEventTable_019e6599-8623-777c-815c-26f46e560e69" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-70dc-94d8-a2bc6cd83400" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-70dc-94d8-a2bc6cd83400_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-70dc-94d8-a2bc6cd83400" xlink:to="loc_dei_EntityDomain_019e6599-8623-70dc-94d8-a2bc6cd83400_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7abd-999c-40036a9c0bb7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-70dc-94d8-a2bc6cd83400" xlink:to="loc_dei_EntityDomain_019e6599-8623-7abd-999c-40036a9c0bb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7820-ad15-36670891c979" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7abd-999c-40036a9c0bb7" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7820-ad15-36670891c979" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock_019e6599-8623-749f-95e3-6eb9f65fbb3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EbpSubsequentEventLineItems_019e6599-8623-701c-aa82-5c8fbe4a6484" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock_019e6599-8623-749f-95e3-6eb9f65fbb3e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYear" xlink:type="simple" xlink:href="oxy-20260629.xsd#ScheduleHLine4iScheduleofAssetsHeldatEndofYear"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYear" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-798f-92ba-fb19ddc0ad52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-71ca-86af-5eb269ac1a5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-798f-92ba-fb19ddc0ad52" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-71ca-86af-5eb269ac1a5c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7278-928c-ae76cd34674f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-71ca-86af-5eb269ac1a5c" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7278-928c-ae76cd34674f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7278-928c-ae76cd34674f_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7278-928c-ae76cd34674f" xlink:to="loc_dei_EntityDomain_019e6599-8623-7278-928c-ae76cd34674f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7afa-a8a4-81fc893147be" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7278-928c-ae76cd34674f" xlink:to="loc_dei_EntityDomain_019e6599-8623-7afa-a8a4-81fc893147be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7f0f-b499-f29faa932b48" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7afa-a8a4-81fc893147be" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7f0f-b499-f29faa932b48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTableTextBlock_019e6599-8623-7d9b-95e8-e60d0feb8ab7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-798f-92ba-fb19ddc0ad52" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTableTextBlock_019e6599-8623-7d9b-95e8-e60d0feb8ab7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ScheduleHLine4jScheduleofReportableTransactions" xlink:type="simple" xlink:href="oxy-20260629.xsd#ScheduleHLine4jScheduleofReportableTransactions"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ScheduleHLine4jScheduleofReportableTransactions" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-72cd-8918-e2f8c4c8f8c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7463-8238-a82f3cb54419" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-72cd-8918-e2f8c4c8f8c2" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7463-8238-a82f3cb54419" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-78f1-aa1f-6c2ad1966cc7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7463-8238-a82f3cb54419" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-78f1-aa1f-6c2ad1966cc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-78f1-aa1f-6c2ad1966cc7_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-78f1-aa1f-6c2ad1966cc7" xlink:to="loc_dei_EntityDomain_019e6599-8623-78f1-aa1f-6c2ad1966cc7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7fe2-9a64-9dde3a5fadcd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-78f1-aa1f-6c2ad1966cc7" xlink:to="loc_dei_EntityDomain_019e6599-8623-7fe2-9a64-9dde3a5fadcd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7c2f-b958-738cad7a973b" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7fe2-9a64-9dde3a5fadcd" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7c2f-b958-738cad7a973b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTableTextBlock_019e6599-8623-77c3-99f4-6b4eca6a67b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-72cd-8918-e2f8c4c8f8c2" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTableTextBlock_019e6599-8623-77c3-99f4-6b4eca6a67b8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/SummaryofSignificantAccountingPoliciesPolicies" xlink:type="simple" xlink:href="oxy-20260629.xsd#SummaryofSignificantAccountingPoliciesPolicies"/>
  <link:definitionLink xlink:role="http://oxy.com/role/SummaryofSignificantAccountingPoliciesPolicies" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019e6599-8623-703b-8b81-573945ae9206" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019e6599-8623-703b-8b81-573945ae9206" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7638-80a9-e6a3e6458c55" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019e6599-8623-703b-8b81-573945ae9206" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7638-80a9-e6a3e6458c55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7638-80a9-e6a3e6458c55_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7638-80a9-e6a3e6458c55" xlink:to="loc_dei_EntityDomain_019e6599-8623-7638-80a9-e6a3e6458c55_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7585-b916-39e3f6d559c6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7638-80a9-e6a3e6458c55" xlink:to="loc_dei_EntityDomain_019e6599-8623-7585-b916-39e3f6d559c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-78f4-b176-3fe27ad98c96" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7585-b916-39e3f6d559c6" xlink:to="loc_oxy_EBP001Member_019e6599-8623-78f4-b176-3fe27ad98c96" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock_019e6604-7266-7f17-88ac-d2059b8bd73e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock_019e6604-7266-7f17-88ac-d2059b8bd73e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock_019e6605-0836-7856-80c7-06f94e20ce70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock_019e6605-0836-7856-80c7-06f94e20ce70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock_019e6605-5fea-72d9-af7a-27874068b472" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock_019e6605-5fea-72d9-af7a-27874068b472" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanContributionPolicyTextBlock_019e6609-c0c9-7483-94b1-bceec03d0307" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanContributionPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanContributionPolicyTextBlock_019e6609-c0c9-7483-94b1-bceec03d0307" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock_019e660a-0aeb-746d-9db5-a93e2834a4da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock_019e660a-0aeb-746d-9db5-a93e2834a4da" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantPolicyTextBlock_019e6606-64d4-7471-b80f-213cef170d87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantPolicyTextBlock_019e6606-64d4-7471-b80f-213cef170d87" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPReclassificationsPolicyTextBlock_019e660b-1b77-70f4-865c-b4bf5082681f" xlink:href="oxy-20260629.xsd#oxy_EBPReclassificationsPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019e6599-8623-7c4b-8f89-6e941bcfb47b" xlink:to="loc_oxy_EBPReclassificationsPolicyTextBlock_019e660b-1b77-70f4-865c-b4bf5082681f" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/GuaranteedInvestmentContractsMasterTrustAccountTables" xlink:type="simple" xlink:href="oxy-20260629.xsd#GuaranteedInvestmentContractsMasterTrustAccountTables"/>
  <link:definitionLink xlink:role="http://oxy.com/role/GuaranteedInvestmentContractsMasterTrustAccountTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019e6ff0-d4c3-7919-82c0-a1f29742ca9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable_019e6ff0-d4c3-7ec8-907e-44b98e02dc46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019e6ff0-d4c3-7919-82c0-a1f29742ca9d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable_019e6ff0-d4c3-7ec8-907e-44b98e02dc46" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6ff0-d4c3-7f23-8b15-36f8189ee5c1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTable_019e6ff0-d4c3-7ec8-907e-44b98e02dc46" xlink:to="loc_dei_LegalEntityAxis_019e6ff0-d4c3-7f23-8b15-36f8189ee5c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6ff0-d4c3-7f23-8b15-36f8189ee5c1_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6ff0-d4c3-7f23-8b15-36f8189ee5c1" xlink:to="loc_dei_EntityDomain_019e6ff0-d4c3-7f23-8b15-36f8189ee5c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6ff0-d4c3-7410-b30d-9faee6bf68f2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6ff0-d4c3-7f23-8b15-36f8189ee5c1" xlink:to="loc_dei_EntityDomain_019e6ff0-d4c3-7410-b30d-9faee6bf68f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6ff0-ecb9-7e7f-aa09-0c1911d8415b" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6ff0-d4c3-7410-b30d-9faee6bf68f2" xlink:to="loc_oxy_EBP001Member_019e6ff0-ecb9-7e7f-aa09-0c1911d8415b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTableTextBlock_019e6ff0-d4c3-7e97-baa3-a2cb1c474fd8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019e6ff0-d4c3-7919-82c0-a1f29742ca9d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTableTextBlock_019e6ff0-d4c3-7e97-baa3-a2cb1c474fd8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/OxyStockFundTables" xlink:type="simple" xlink:href="oxy-20260629.xsd#OxyStockFundTables"/>
  <link:definitionLink xlink:role="http://oxy.com/role/OxyStockFundTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e8f55-05b3-7955-9025-3eaf24b11341" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e8f55-05b3-708c-b22e-26839250580c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e8f55-05b3-7955-9025-3eaf24b11341" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e8f55-05b3-708c-b22e-26839250580c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e8f55-05b3-79c6-8107-f31f12a0d34e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e8f55-05b3-708c-b22e-26839250580c" xlink:to="loc_dei_LegalEntityAxis_019e8f55-05b3-79c6-8107-f31f12a0d34e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e8f55-05b3-79c6-8107-f31f12a0d34e_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e8f55-05b3-79c6-8107-f31f12a0d34e" xlink:to="loc_dei_EntityDomain_019e8f55-05b3-79c6-8107-f31f12a0d34e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e8f55-05b3-7fde-8cda-56fbc3bdff26" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e8f55-05b3-79c6-8107-f31f12a0d34e" xlink:to="loc_dei_EntityDomain_019e8f55-05b3-7fde-8cda-56fbc3bdff26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e8f55-424b-7890-ba3d-7ac8f06fcd6c" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e8f55-05b3-7fde-8cda-56fbc3bdff26" xlink:to="loc_oxy_EBP001Member_019e8f55-424b-7890-ba3d-7ac8f06fcd6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanContributionTableTextBlock_019e8f55-05b3-7bc8-a9ac-5340c29d9cbf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanContributionTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e8f55-05b3-7955-9025-3eaf24b11341" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanContributionTableTextBlock_019e8f55-05b3-7bc8-a9ac-5340c29d9cbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock_019e8490-1960-7ee2-a5c1-6a79fce48517" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e8f55-05b3-7955-9025-3eaf24b11341" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock_019e8490-1960-7ee2-a5c1-6a79fce48517" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanInterestinMasterTrustAccountsTables" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanInterestinMasterTrustAccountsTables"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanInterestinMasterTrustAccountsTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7d28-ad75-848e44f570ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-79ae-a9bb-8f1468753994" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7d28-ad75-848e44f570ab" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-79ae-a9bb-8f1468753994" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7d1b-8c31-4f555b5f2458" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-79ae-a9bb-8f1468753994" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7d1b-8c31-4f555b5f2458" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7d1b-8c31-4f555b5f2458_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7d1b-8c31-4f555b5f2458" xlink:to="loc_dei_EntityDomain_019e6599-8623-7d1b-8c31-4f555b5f2458_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7d67-b91e-b9b3e7ecdf6f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7d1b-8c31-4f555b5f2458" xlink:to="loc_dei_EntityDomain_019e6599-8623-7d67-b91e-b9b3e7ecdf6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-788a-8da9-6ff38a4867c6" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7d67-b91e-b9b3e7ecdf6f" xlink:to="loc_oxy_EBP001Member_019e6599-8623-788a-8da9-6ff38a4867c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTableTextBlock_019e6599-8623-71f0-ae66-39ba78b51874" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7d28-ad75-848e44f570ab" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTableTextBlock_019e6599-8623-71f0-ae66-39ba78b51874" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500Tables" xlink:type="simple" xlink:href="oxy-20260629.xsd#ReconciliationoftheFinancialStatementstotheForm5500Tables"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500Tables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-749e-bf97-1c01826e4654" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-7136-8bcd-3ffef6be3c16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-749e-bf97-1c01826e4654" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-7136-8bcd-3ffef6be3c16" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7cf8-a13a-ccc994951bca" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-7136-8bcd-3ffef6be3c16" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7cf8-a13a-ccc994951bca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7cf8-a13a-ccc994951bca_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7cf8-a13a-ccc994951bca" xlink:to="loc_dei_EntityDomain_019e6599-8623-7cf8-a13a-ccc994951bca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7445-bf2c-94110a3a4fa2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7cf8-a13a-ccc994951bca" xlink:to="loc_dei_EntityDomain_019e6599-8623-7445-bf2c-94110a3a4fa2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-702d-bab2-91380eb0ae55" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7445-bf2c-94110a3a4fa2" xlink:to="loc_oxy_EBP001Member_019e6599-8623-702d-bab2-91380eb0ae55" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500TableTextBlock_019e6599-8623-7679-a1ee-950276f54dd1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500TableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-749e-bf97-1c01826e4654" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500TableTextBlock_019e6599-8623-7679-a1ee-950276f54dd1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/DescriptionofthePlanDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#DescriptionofthePlanDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/DescriptionofthePlanDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-72e2-b272-2db743e00b4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-72e2-b272-2db743e00b4b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7a8c-a62d-6871772fab27" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-72e2-b272-2db743e00b4b" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7a8c-a62d-6871772fab27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7a8c-a62d-6871772fab27_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7a8c-a62d-6871772fab27" xlink:to="loc_dei_EntityDomain_019e6599-8623-7a8c-a62d-6871772fab27_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7a1f-8648-ed33b6baabe0" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7a8c-a62d-6871772fab27" xlink:to="loc_dei_EntityDomain_019e6599-8623-7a1f-8648-ed33b6baabe0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-78db-afde-887b3ab328d4" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7a1f-8648-ed33b6baabe0" xlink:to="loc_oxy_EBP001Member_019e6599-8623-78db-afde-887b3ab328d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019e6f3a-3e4a-78ae-be0c-01fadc60c822" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_019e6599-8623-72e2-b272-2db743e00b4b" xlink:to="loc_srt_RangeAxis_019e6f3a-3e4a-78ae-be0c-01fadc60c822" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e6f3a-3e4a-78ae-be0c-01fadc60c822_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019e6f3a-3e4a-78ae-be0c-01fadc60c822" xlink:to="loc_srt_RangeMember_019e6f3a-3e4a-78ae-be0c-01fadc60c822_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e6f3a-3e4a-7143-97e2-df398e5a3c21" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019e6f3a-3e4a-78ae-be0c-01fadc60c822" xlink:to="loc_srt_RangeMember_019e6f3a-3e4a-7143-97e2-df398e5a3c21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019e6f3a-50d4-7088-9388-d8493d15f100" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e6f3a-3e4a-7143-97e2-df398e5a3c21" xlink:to="loc_srt_MinimumMember_019e6f3a-50d4-7088-9388-d8493d15f100" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019e6f45-abcb-7aa5-9e3f-ec48e4c1c244" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e6f3a-3e4a-7143-97e2-df398e5a3c21" xlink:to="loc_srt_MaximumMember_019e6f45-abcb-7aa5-9e3f-ec48e4c1c244" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNotHighlyCompensatedParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage_019e6f3c-e418-7345-abaf-6ebb81551089" xlink:href="oxy-20260629.xsd#oxy_EBPNotHighlyCompensatedParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPNotHighlyCompensatedParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage_019e6f3c-e418-7345-abaf-6ebb81551089" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPHighlyCompensatedParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage_019e6f3d-35bd-74b5-9aba-3f2a896a8b0d" xlink:href="oxy-20260629.xsd#oxy_EBPHighlyCompensatedParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPHighlyCompensatedParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage_019e6f3d-35bd-74b5-9aba-3f2a896a8b0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate_019e6f3a-0fd4-70da-bd1b-ab705c0d291b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate_019e6f3a-0fd4-70da-bd1b-ab705c0d291b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPEmployerContributionFirstMatchingPercentage_019e6f43-8bb2-7842-8c11-14cd249eba94" xlink:href="oxy-20260629.xsd#oxy_EBPEmployerContributionFirstMatchingPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPEmployerContributionFirstMatchingPercentage_019e6f43-8bb2-7842-8c11-14cd249eba94" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPEmployerContributionFirstParticipantCompensationMatchedPercentage_019e6f44-4b4e-7c4e-b708-050b94965fb7" xlink:href="oxy-20260629.xsd#oxy_EBPEmployerContributionFirstParticipantCompensationMatchedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPEmployerContributionFirstParticipantCompensationMatchedPercentage_019e6f44-4b4e-7c4e-b708-050b94965fb7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPEmployerContributionSecondMatchingPercentage_019e6f44-d725-7bf1-8d74-7e45090dded8" xlink:href="oxy-20260629.xsd#oxy_EBPEmployerContributionSecondMatchingPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPEmployerContributionSecondMatchingPercentage_019e6f44-d725-7bf1-8d74-7e45090dded8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPEmployerContributionSecondParticipantCompensationMatchedPercentage_019e6f44-8eb8-72d8-961b-8e35633e4f81" xlink:href="oxy-20260629.xsd#oxy_EBPEmployerContributionSecondParticipantCompensationMatchedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPEmployerContributionSecondParticipantCompensationMatchedPercentage_019e6f44-8eb8-72d8-961b-8e35633e4f81" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage_019e6f45-7559-7b15-b405-d18392b6bdfa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage_019e6f45-7559-7b15-b405-d18392b6bdfa" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage_019e6f45-f2d4-7654-ab52-a0ee7bff308e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage_019e6f45-f2d4-7654-ab52-a0ee7bff308e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingAmount_019e6f49-14fc-7361-95aa-316d63fc8ff7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingAmount_019e6f49-14fc-7361-95aa-316d63fc8ff7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount_019e6f7b-6cba-7813-ac67-8f5a061244a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount_019e6f7b-6cba-7813-ac67-8f5a061244a0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage_019e6f49-4cc9-714b-9df9-9daac4559822" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage_019e6f49-4cc9-714b-9df9-9daac4559822" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNoteReceivableFromParticipantMonthlyPayrollDeductionMonthlyCompensationMaximumPercentage_019e6f4b-4a7f-70eb-9770-74d90863543d" xlink:href="oxy-20260629.xsd#oxy_EBPNoteReceivableFromParticipantMonthlyPayrollDeductionMonthlyCompensationMaximumPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPNoteReceivableFromParticipantMonthlyPayrollDeductionMonthlyCompensationMaximumPercentage_019e6f4b-4a7f-70eb-9770-74d90863543d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNoteReceivableFromParticipantGeneralLoanMinimumBorrowingTerm_019e6f78-3bce-7f42-b844-f4ff0aa9eeed" xlink:href="oxy-20260629.xsd#oxy_EBPNoteReceivableFromParticipantGeneralLoanMinimumBorrowingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPNoteReceivableFromParticipantGeneralLoanMinimumBorrowingTerm_019e6f78-3bce-7f42-b844-f4ff0aa9eeed" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNoteReceivableFromParticipantGeneralLoanMaximumBorrowingTerm_019e6f78-934d-7021-9dd0-4a1f485c4d5b" xlink:href="oxy-20260629.xsd#oxy_EBPNoteReceivableFromParticipantGeneralLoanMaximumBorrowingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPNoteReceivableFromParticipantGeneralLoanMaximumBorrowingTerm_019e6f78-934d-7021-9dd0-4a1f485c4d5b" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMinimumBorrowingTerm_019e6f79-6634-70b6-a1ef-170b8651df28" xlink:href="oxy-20260629.xsd#oxy_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMinimumBorrowingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMinimumBorrowingTerm_019e6f79-6634-70b6-a1ef-170b8651df28" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMaximumBorrowingTerm_019e6f79-d57c-758a-96d7-49c2565a87c7" xlink:href="oxy-20260629.xsd#oxy_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMaximumBorrowingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_oxy_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMaximumBorrowingTerm_019e6f79-d57c-758a-96d7-49c2565a87c7" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate_019e6f7a-63bb-7f62-9f15-95eabaa44f9b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019e6599-8623-7c7e-ad26-84f32aca02b9" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate_019e6f7a-63bb-7f62-9f15-95eabaa44f9b" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/GuaranteedInvestmentContractsMasterTrustAccountDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#GuaranteedInvestmentContractsMasterTrustAccountDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/GuaranteedInvestmentContractsMasterTrustAccountDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019efb02-c424-7a30-b94b-1324c5d0cf1d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019efb02-c424-7794-a69d-125b8e7b45ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019efb02-c424-7a30-b94b-1324c5d0cf1d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019efb02-c424-7794-a69d-125b8e7b45ea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019efb02-c424-7d01-956d-a7b3164b610a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019efb02-c424-7794-a69d-125b8e7b45ea" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019efb02-c424-7d01-956d-a7b3164b610a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019efb02-c424-7d01-956d-a7b3164b610a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019efb02-c424-7d01-956d-a7b3164b610a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019efb02-c424-7d01-956d-a7b3164b610a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019efb02-c424-7c9c-a512-00d8003475aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019efb02-c424-7d01-956d-a7b3164b610a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019efb02-c424-7c9c-a512-00d8003475aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember_019efb02-c424-7d5d-af0a-188ed81df1de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019efb02-c424-7c9c-a512-00d8003475aa" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember_019efb02-c424-7d5d-af0a-188ed81df1de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019efb02-c424-7053-aafd-b62f58dadf1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019efb02-c424-7794-a69d-125b8e7b45ea" xlink:to="loc_us-gaap_InvestmentTypeAxis_019efb02-c424-7053-aafd-b62f58dadf1c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019efb02-c424-7053-aafd-b62f58dadf1c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019efb02-c424-7053-aafd-b62f58dadf1c" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019efb02-c424-7053-aafd-b62f58dadf1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019efb02-c424-7221-a3b7-9bf948462ec8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019efb02-c424-7053-aafd-b62f58dadf1c" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019efb02-c424-7221-a3b7-9bf948462ec8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_019efb02-c424-75dc-af37-8f851d289898" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019efb02-c424-7221-a3b7-9bf948462ec8" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_019efb02-c424-75dc-af37-8f851d289898" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019efb02-c424-75b5-b3f0-555e2113d913" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019efb02-c424-7221-a3b7-9bf948462ec8" xlink:to="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019efb02-c424-75b5-b3f0-555e2113d913" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019efb02-c424-7301-9fa0-f424cd61e128" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019efb02-c424-7794-a69d-125b8e7b45ea" xlink:to="loc_dei_LegalEntityAxis_019efb02-c424-7301-9fa0-f424cd61e128" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019efb02-c424-7301-9fa0-f424cd61e128_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019efb02-c424-7301-9fa0-f424cd61e128" xlink:to="loc_dei_EntityDomain_019efb02-c424-7301-9fa0-f424cd61e128_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019efb02-c424-78d8-bc6f-b7a4d9a47dc6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019efb02-c424-7301-9fa0-f424cd61e128" xlink:to="loc_dei_EntityDomain_019efb02-c424-78d8-bc6f-b7a4d9a47dc6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019efb02-c424-7b81-b1e6-b34595011f2f" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019efb02-c424-78d8-bc6f-b7a4d9a47dc6" xlink:to="loc_oxy_EBP001Member_019efb02-c424-7b81-b1e6-b34595011f2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue_019efb02-c424-7e83-b228-e0eb2af19430" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019efb02-c424-7a30-b94b-1324c5d0cf1d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue_019efb02-c424-7e83-b228-e0eb2af19430" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/OxyStockFundNetAssetsDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#OxyStockFundNetAssetsDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/OxyStockFundNetAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e84a1-1b0e-75aa-beb1-0612be14719a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e84a1-1b0e-7d30-b59c-398476a628e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e84a1-1b0e-75aa-beb1-0612be14719a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e84a1-1b0e-7d30-b59c-398476a628e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e84a1-1b0e-7e65-8f91-f0cc366525b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e84a1-1b0e-7d30-b59c-398476a628e7" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e84a1-1b0e-7e65-8f91-f0cc366525b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e84a1-1b0e-7e65-8f91-f0cc366525b7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e84a1-1b0e-7e65-8f91-f0cc366525b7" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e84a1-1b0e-7e65-8f91-f0cc366525b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e84a1-1b0e-7ca5-9016-ab11c18ba54a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e84a1-1b0e-7e65-8f91-f0cc366525b7" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e84a1-1b0e-7ca5-9016-ab11c18ba54a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_019e84a1-1b0e-79cc-af78-5a0f829c3593" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e84a1-1b0e-7ca5-9016-ab11c18ba54a" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_019e84a1-1b0e-79cc-af78-5a0f829c3593" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e84a1-1b0e-71a2-b953-8219a49b1189" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e84a1-1b0e-7ca5-9016-ab11c18ba54a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e84a1-1b0e-71a2-b953-8219a49b1189" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e84a1-1b0e-7c3a-89c5-03a3d3d9d732" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e84a1-1b0e-7d30-b59c-398476a628e7" xlink:to="loc_dei_LegalEntityAxis_019e84a1-1b0e-7c3a-89c5-03a3d3d9d732" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e84a1-1b0e-7c3a-89c5-03a3d3d9d732_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e84a1-1b0e-7c3a-89c5-03a3d3d9d732" xlink:to="loc_dei_EntityDomain_019e84a1-1b0e-7c3a-89c5-03a3d3d9d732_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e84a1-1b0e-783a-a742-476975e74b57" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e84a1-1b0e-7c3a-89c5-03a3d3d9d732" xlink:to="loc_dei_EntityDomain_019e84a1-1b0e-783a-a742-476975e74b57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e84a1-1b0e-7403-a648-1b4ab808608b" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e84a1-1b0e-783a-a742-476975e74b57" xlink:to="loc_oxy_EBP001Member_019e84a1-1b0e-7403-a648-1b4ab808608b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPStockFundNameAxis_019edbeb-00ca-7d5d-99cc-14e933a67c39" xlink:href="oxy-20260629.xsd#oxy_EBPStockFundNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTable_019e84a1-1b0e-7d30-b59c-398476a628e7" xlink:to="loc_oxy_EBPStockFundNameAxis_019edbeb-00ca-7d5d-99cc-14e933a67c39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPStockFundNameDomain_019edbeb-00ca-7d5d-99cc-14e933a67c39_default" xlink:href="oxy-20260629.xsd#oxy_EBPStockFundNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_oxy_EBPStockFundNameAxis_019edbeb-00ca-7d5d-99cc-14e933a67c39" xlink:to="loc_oxy_EBPStockFundNameDomain_019edbeb-00ca-7d5d-99cc-14e933a67c39_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPStockFundNameDomain_019edbeb-00ca-7ae8-8469-c2fa09e3e865" xlink:href="oxy-20260629.xsd#oxy_EBPStockFundNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_oxy_EBPStockFundNameAxis_019edbeb-00ca-7d5d-99cc-14e933a67c39" xlink:to="loc_oxy_EBPStockFundNameDomain_019edbeb-00ca-7ae8-8469-c2fa09e3e865" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_OxyStockFundMember_019edbeb-3a07-7fc8-8e2d-49c0c91726a9" xlink:href="oxy-20260629.xsd#oxy_OxyStockFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPStockFundNameDomain_019edbeb-00ca-7ae8-8469-c2fa09e3e865" xlink:to="loc_oxy_OxyStockFundMember_019edbeb-3a07-7fc8-8e2d-49c0c91726a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e84c3-f159-743d-afdc-9bbd8d336343" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e84a1-1b0e-75aa-beb1-0612be14719a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e84c3-f159-743d-afdc-9bbd8d336343" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue_019e84a1-1b0e-707e-ac1e-36704224b6c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e84c3-f159-743d-afdc-9bbd8d336343" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue_019e84a1-1b0e-707e-ac1e-36704224b6c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable_019e84a1-1b0e-7cca-bb51-79d5685bf6fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e84c3-f159-743d-afdc-9bbd8d336343" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable_019e84a1-1b0e-7cca-bb51-79d5685bf6fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAsset_019e84a1-1b0e-7262-8c20-601ed0d01ec4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e84c3-f159-743d-afdc-9bbd8d336343" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAsset_019e84a1-1b0e-7262-8c20-601ed0d01ec4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e84a1-1b0e-75aa-beb1-0612be14719a" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution_019e84a1-1b0e-7fcd-93ce-c47b84c2678d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution_019e84a1-1b0e-7fcd-93ce-c47b84c2678d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment_019e84a1-1b0e-749c-8e3b-6ead484f2b5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment_019e84a1-1b0e-749c-8e3b-6ead484f2b5a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019e84a1-1b0e-71da-98d0-809ac678867a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019e84a1-1b0e-71da-98d0-809ac678867a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForChangeInPlanInterestInMasterTrust_019e84a1-1b0e-7361-8ec9-48f6490d369e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForChangeInPlanInterestInMasterTrust"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForChangeInPlanInterestInMasterTrust_019e84a1-1b0e-7361-8ec9-48f6490d369e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019e84a1-1b0e-7a5f-8630-6f63b2f4814d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019e84a1-1b0e-7a5f-8630-6f63b2f4814d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense_019e84a1-1b0e-78cc-99ff-3887d4edea06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense_019e84a1-1b0e-78cc-99ff-3887d4edea06" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019e84a1-1b0e-7187-99cd-283868993aad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e84c4-c9d6-7bf3-9a45-657f20779f13" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019e84a1-1b0e-7187-99cd-283868993aad" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/OxyStockFundFairValueMeasurementDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#OxyStockFundFairValueMeasurementDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/OxyStockFundFairValueMeasurementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e8492-de0f-7282-8d13-fcd6f1d0093d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e8492-de0f-754a-9fbf-22f1ddf10e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e8492-de0f-7282-8d13-fcd6f1d0093d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e8492-de0f-754a-9fbf-22f1ddf10e9a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8492-de0f-73d6-bfdf-16a5f598cf99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e8492-de0f-754a-9fbf-22f1ddf10e9a" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8492-de0f-73d6-bfdf-16a5f598cf99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8492-de0f-73d6-bfdf-16a5f598cf99_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8492-de0f-73d6-bfdf-16a5f598cf99" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8492-de0f-73d6-bfdf-16a5f598cf99_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8492-de0f-7358-8b01-c71b12684b03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e8492-de0f-73d6-bfdf-16a5f598cf99" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8492-de0f-7358-8b01-c71b12684b03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel12And3Member_019e84a6-ef9f-7805-bb99-cc62ad9f527f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel12And3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8492-de0f-7358-8b01-c71b12684b03" xlink:to="loc_us-gaap_FairValueInputsLevel12And3Member_019e84a6-ef9f-7805-bb99-cc62ad9f527f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019e8492-de0f-7139-a01f-6a9499f03903" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueInputsLevel12And3Member_019e84a6-ef9f-7805-bb99-cc62ad9f527f" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019e8492-de0f-7139-a01f-6a9499f03903" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_019e8492-de0f-7a73-b411-52b5193d48c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e8492-de0f-7358-8b01-c71b12684b03" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_019e8492-de0f-7a73-b411-52b5193d48c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e8492-de0f-70bf-910e-697ff25be71a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e8492-de0f-754a-9fbf-22f1ddf10e9a" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e8492-de0f-70bf-910e-697ff25be71a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e8492-de0f-70bf-910e-697ff25be71a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e8492-de0f-70bf-910e-697ff25be71a" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e8492-de0f-70bf-910e-697ff25be71a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e8492-de0f-7dee-9ce5-5456c9717064" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e8492-de0f-70bf-910e-697ff25be71a" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e8492-de0f-7dee-9ce5-5456c9717064" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e8492-de0f-7b5e-9362-4a6dc0a03c0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e8492-de0f-7dee-9ce5-5456c9717064" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e8492-de0f-7b5e-9362-4a6dc0a03c0c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_019e8492-de0f-75bb-b123-214ce0c02396" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e8492-de0f-7dee-9ce5-5456c9717064" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_019e8492-de0f-75bb-b123-214ce0c02396" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e8492-de0f-7e0e-a2a3-3f7899c31634" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e8492-de0f-754a-9fbf-22f1ddf10e9a" xlink:to="loc_dei_LegalEntityAxis_019e8492-de0f-7e0e-a2a3-3f7899c31634" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e8492-de0f-7e0e-a2a3-3f7899c31634_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e8492-de0f-7e0e-a2a3-3f7899c31634" xlink:to="loc_dei_EntityDomain_019e8492-de0f-7e0e-a2a3-3f7899c31634_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e8492-de0f-7052-acd8-5e691ff32093" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e8492-de0f-7e0e-a2a3-3f7899c31634" xlink:to="loc_dei_EntityDomain_019e8492-de0f-7052-acd8-5e691ff32093" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e8492-de0f-7eaf-91c8-4ac001bf429e" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e8492-de0f-7052-acd8-5e691ff32093" xlink:to="loc_oxy_EBP001Member_019e8492-de0f-7eaf-91c8-4ac001bf429e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPStockFundNameAxis_019edbec-d626-7914-bb4c-f0ac9cc793ab" xlink:href="oxy-20260629.xsd#oxy_EBPStockFundNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e8492-de0f-754a-9fbf-22f1ddf10e9a" xlink:to="loc_oxy_EBPStockFundNameAxis_019edbec-d626-7914-bb4c-f0ac9cc793ab" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPStockFundNameDomain_019edbec-d626-7914-bb4c-f0ac9cc793ab_default" xlink:href="oxy-20260629.xsd#oxy_EBPStockFundNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_oxy_EBPStockFundNameAxis_019edbec-d626-7914-bb4c-f0ac9cc793ab" xlink:to="loc_oxy_EBPStockFundNameDomain_019edbec-d626-7914-bb4c-f0ac9cc793ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPStockFundNameDomain_019edbec-d626-7dd9-92f5-062ed66ad79a" xlink:href="oxy-20260629.xsd#oxy_EBPStockFundNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_oxy_EBPStockFundNameAxis_019edbec-d626-7914-bb4c-f0ac9cc793ab" xlink:to="loc_oxy_EBPStockFundNameDomain_019edbec-d626-7dd9-92f5-062ed66ad79a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_OxyStockFundMember_019edbec-e67f-727d-a107-ec1c8dc6fe16" xlink:href="oxy-20260629.xsd#oxy_OxyStockFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPStockFundNameDomain_019edbec-d626-7dd9-92f5-062ed66ad79a" xlink:to="loc_oxy_OxyStockFundMember_019edbec-e67f-727d-a107-ec1c8dc6fe16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e8492-de0f-779b-898b-ff9fac05b5e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e8492-de0f-7282-8d13-fcd6f1d0093d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e8492-de0f-779b-898b-ff9fac05b5e8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanInterestinMasterTrustAccountsScheduleofMasterTrustNetAssetsDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanInterestinMasterTrustAccountsScheduleofMasterTrustNetAssetsDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanInterestinMasterTrustAccountsScheduleofMasterTrustNetAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7b45-8f32-9a2c4a6fd7c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7558-ba75-782a3d597676" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7b45-8f32-9a2c4a6fd7c6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7558-ba75-782a3d597676" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7e12-815b-cec218e00de7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7558-ba75-782a3d597676" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7e12-815b-cec218e00de7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7e12-815b-cec218e00de7_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7e12-815b-cec218e00de7" xlink:to="loc_dei_EntityDomain_019e6599-8623-7e12-815b-cec218e00de7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7efd-b666-7236d4b22540" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7e12-815b-cec218e00de7" xlink:to="loc_dei_EntityDomain_019e6599-8623-7efd-b666-7236d4b22540" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7081-b13c-82eff7d5b399" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7efd-b666-7236d4b22540" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7081-b13c-82eff7d5b399" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e7079-a065-7040-9ecf-55e928a75788" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6599-8623-7558-ba75-782a3d597676" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e7079-a065-7040-9ecf-55e928a75788" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e7079-a065-7040-9ecf-55e928a75788_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e7079-a065-7040-9ecf-55e928a75788" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e7079-a065-7040-9ecf-55e928a75788_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e7079-a065-7c11-914b-c402a7a9b440" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e7079-a065-7040-9ecf-55e928a75788" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e7079-a065-7c11-914b-c402a7a9b440" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedPlanInterestInMasterTrustMember_019e7079-be6a-75a0-ac9a-d1b5ac9c78b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedPlanInterestInMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e7079-a065-7c11-914b-c402a7a9b440" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedPlanInterestInMasterTrustMember_019e7079-be6a-75a0-ac9a-d1b5ac9c78b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e6f2b-38df-75eb-896f-a67e73b6f560" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7b45-8f32-9a2c4a6fd7c6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e6f2b-38df-75eb-896f-a67e73b6f560" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue_019e6fe5-9ca5-749d-8f56-1c12fed184b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7b45-8f32-9a2c4a6fd7c6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue_019e6fe5-9ca5-749d-8f56-1c12fed184b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e6f2a-29c8-7e65-ae7e-f8659f853bea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6599-8623-7b45-8f32-9a2c4a6fd7c6" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e6f2a-29c8-7e65-ae7e-f8659f853bea" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanInterestinMasterTrustAccountsScheduleofNetAssetsHeldDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanInterestinMasterTrustAccountsScheduleofNetAssetsHeldDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanInterestinMasterTrustAccountsScheduleofNetAssetsHeldDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6f2d-32ac-743d-9427-f8a563ebffcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6f2d-32ac-7b32-b770-a294b9134449" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6f2d-32ac-743d-9427-f8a563ebffcc" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6f2d-32ac-7b32-b770-a294b9134449" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6f2d-32ac-76e3-8de4-3e793fb8701b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6f2d-32ac-7b32-b770-a294b9134449" xlink:to="loc_dei_LegalEntityAxis_019e6f2d-32ac-76e3-8de4-3e793fb8701b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6f2d-32ac-76e3-8de4-3e793fb8701b_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6f2d-32ac-76e3-8de4-3e793fb8701b" xlink:to="loc_dei_EntityDomain_019e6f2d-32ac-76e3-8de4-3e793fb8701b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6f2d-32ac-70b8-a58e-0dccf033237a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6f2d-32ac-76e3-8de4-3e793fb8701b" xlink:to="loc_dei_EntityDomain_019e6f2d-32ac-70b8-a58e-0dccf033237a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6f2d-560e-7c6a-9b54-f3a639cd8591" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6f2d-32ac-70b8-a58e-0dccf033237a" xlink:to="loc_oxy_EBP001Member_019e6f2d-560e-7c6a-9b54-f3a639cd8591" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e6f2d-32ac-72b7-9c45-5cf86c456962" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6f2d-32ac-7b32-b770-a294b9134449" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e6f2d-32ac-72b7-9c45-5cf86c456962" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e6f2d-32ac-72b7-9c45-5cf86c456962_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e6f2d-32ac-72b7-9c45-5cf86c456962" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e6f2d-32ac-72b7-9c45-5cf86c456962_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e6f2d-32ac-7419-86ed-eb8fd91d2823" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis_019e6f2d-32ac-72b7-9c45-5cf86c456962" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e6f2d-32ac-7419-86ed-eb8fd91d2823" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember_019e6f2d-e649-7e75-b9c8-9a920bc2278e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e6f2d-32ac-7419-86ed-eb8fd91d2823" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember_019e6f2d-e649-7e75-b9c8-9a920bc2278e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedPlanInterestInMasterTrustMember_019e6f2d-f9a1-74c1-adf5-66e998df80e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedPlanInterestInMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustDomain_019e6f2d-32ac-7419-86ed-eb8fd91d2823" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedPlanInterestInMasterTrustMember_019e6f2d-f9a1-74c1-adf5-66e998df80e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e6fdf-d70b-7c6f-9b83-521fc5b5cfa5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6f2d-32ac-7b32-b770-a294b9134449" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e6fdf-d70b-7c6f-9b83-521fc5b5cfa5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7c6f-9b83-521fc5b5cfa5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e6fdf-d70b-7c6f-9b83-521fc5b5cfa5" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7c6f-9b83-521fc5b5cfa5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7f40-b6e2-4de0ab39fccc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e6fdf-d70b-7c6f-9b83-521fc5b5cfa5" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7f40-b6e2-4de0ab39fccc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_019e6fe0-1a19-7b70-b0dd-230583554822" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7f40-b6e2-4de0ab39fccc" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_019e6fe0-1a19-7b70-b0dd-230583554822" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e6fe0-469d-713c-9c21-53d76b40f38c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7f40-b6e2-4de0ab39fccc" xlink:to="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e6fe0-469d-713c-9c21-53d76b40f38c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849e-d4f2-78ba-b0b4-c59b969373a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7f40-b6e2-4de0ab39fccc" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849e-d4f2-78ba-b0b4-c59b969373a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019e6fe0-93ca-7fdb-bead-f06388b0dd46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fdf-d70b-7f40-b6e2-4de0ab39fccc" xlink:to="loc_us-gaap_MutualFundMember_019e6fe0-93ca-7fdb-bead-f06388b0dd46" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameAxis_019e704c-bc6d-7568-bc5e-a154fad6e5d0" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6f2d-32ac-7b32-b770-a294b9134449" xlink:to="loc_oxy_EBPMasterTrustNameAxis_019e704c-bc6d-7568-bc5e-a154fad6e5d0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameDomain_019e704c-bc6d-7568-bc5e-a154fad6e5d0_default" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_oxy_EBPMasterTrustNameAxis_019e704c-bc6d-7568-bc5e-a154fad6e5d0" xlink:to="loc_oxy_EBPMasterTrustNameDomain_019e704c-bc6d-7568-bc5e-a154fad6e5d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameDomain_019e704c-bc6d-7a74-a1f3-c2d2e1008da0" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_oxy_EBPMasterTrustNameAxis_019e704c-bc6d-7568-bc5e-a154fad6e5d0" xlink:to="loc_oxy_EBPMasterTrustNameDomain_019e704c-bc6d-7a74-a1f3-c2d2e1008da0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_DefinedContributionPlanMasterTrustMember_019e7053-6a66-751e-a390-b40268903a12" xlink:href="oxy-20260629.xsd#oxy_DefinedContributionPlanMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPMasterTrustNameDomain_019e704c-bc6d-7a74-a1f3-c2d2e1008da0" xlink:to="loc_oxy_DefinedContributionPlanMasterTrustMember_019e7053-6a66-751e-a390-b40268903a12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_GuaranteedInvestmentContractsMasterTrustInvestmentAccountMember_019e7061-09c8-7449-89a7-3c83abb4bfd5" xlink:href="oxy-20260629.xsd#oxy_GuaranteedInvestmentContractsMasterTrustInvestmentAccountMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPMasterTrustNameDomain_019e704c-bc6d-7a74-a1f3-c2d2e1008da0" xlink:to="loc_oxy_GuaranteedInvestmentContractsMasterTrustInvestmentAccountMember_019e7061-09c8-7449-89a7-3c83abb4bfd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6f2d-32ac-743d-9427-f8a563ebffcc" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e6f31-ed42-7e65-a759-34238bdf16ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e6f31-ed42-7e65-a759-34238bdf16ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e6f2e-c5dc-7604-8ad6-89c68f39d84c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAbstract_019e6f31-ed42-7e65-a759-34238bdf16ef" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e6f2e-c5dc-7604-8ad6-89c68f39d84c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract_019e7063-6ed4-733e-af22-9ba60f7c5023" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract_019e7063-6ed4-733e-af22-9ba60f7c5023" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue_019e7061-09c8-7dcf-b52a-16f8586cd930" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValueAbstract_019e7063-6ed4-733e-af22-9ba60f7c5023" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentContractValue_019e7061-09c8-7dcf-b52a-16f8586cd930" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanCash_019e6f2f-4454-70e1-aee2-b625b67c81e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanCash_019e6f2f-4454-70e1-aee2-b625b67c81e8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e6f32-6287-7309-a786-eeb478f4000d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e6f32-6287-7309-a786-eeb478f4000d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable_019e6f2f-efe6-7e0b-91c5-1a2aa497a904" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e6f32-6287-7309-a786-eeb478f4000d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentIncomeReceivable_019e6f2f-efe6-7e0b-91c5-1a2aa497a904" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReceivable_019e7061-09c8-7971-a12a-783144fa4027" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivableAbstract_019e6f32-6287-7309-a786-eeb478f4000d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReceivable_019e7061-09c8-7971-a12a-783144fa4027" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAsset_019e6f30-08cd-7e50-b6e5-3263e80abfee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e6f31-889f-74b0-98eb-00c48868e221" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAsset_019e6f30-08cd-7e50-b6e5-3263e80abfee" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_019e6f34-3b7b-7acb-bafc-bbe93244045f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6f2d-32ac-743d-9427-f8a563ebffcc" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_019e6f34-3b7b-7acb-bafc-bbe93244045f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityInvestmentPurchase_019e6f30-f86e-7338-81a8-851053b14f81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanLiabilityInvestmentPurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_019e6f34-3b7b-7acb-bafc-bbe93244045f" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityInvestmentPurchase_019e6f30-f86e-7338-81a8-851053b14f81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccruedExpense_019e7061-09c8-76a8-ba6a-de6019705fd9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccruedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_019e6f34-3b7b-7acb-bafc-bbe93244045f" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAccruedExpense_019e7061-09c8-76a8-ba6a-de6019705fd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanLiability_019e6f30-9006-76a2-a2c2-7fcb29a7188a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_019e6f34-3b7b-7acb-bafc-bbe93244045f" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanLiability_019e6f30-9006-76a2-a2c2-7fcb29a7188a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e6f31-3b7f-7891-b695-6925c24a6132" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6f2d-32ac-743d-9427-f8a563ebffcc" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e6f31-3b7f-7891-b695-6925c24a6132" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInterestInMasterTrustPercentage_019e6f2f-9e79-7ab5-adce-adf4a1711490" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInterestInMasterTrustPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6f2d-32ac-743d-9427-f8a563ebffcc" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInterestInMasterTrustPercentage_019e6f2f-9e79-7ab5-adce-adf4a1711490" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanInterestinMasterTrustAccountsChangeinNetAssetsDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanInterestinMasterTrustAccountsChangeinNetAssetsDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanInterestinMasterTrustAccountsChangeinNetAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e706c-992f-7ac1-8d0a-8beeb268c217" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e706c-992f-7ac1-8d0a-8beeb268c217" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e706c-992f-7991-a94a-321e626234b4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e706c-992f-7ac1-8d0a-8beeb268c217" xlink:to="loc_dei_LegalEntityAxis_019e706c-992f-7991-a94a-321e626234b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e706c-992f-7991-a94a-321e626234b4_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e706c-992f-7991-a94a-321e626234b4" xlink:to="loc_dei_EntityDomain_019e706c-992f-7991-a94a-321e626234b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e706c-992f-7f69-9da3-718ce9a200e1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e706c-992f-7991-a94a-321e626234b4" xlink:to="loc_dei_EntityDomain_019e706c-992f-7f69-9da3-718ce9a200e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e706c-992f-77c6-b4e4-b9d17239ec42" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e706c-992f-7f69-9da3-718ce9a200e1" xlink:to="loc_oxy_EBP001Member_019e706c-992f-77c6-b4e4-b9d17239ec42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameAxis_019e706c-992f-702d-baa9-fa67512ae603" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e706c-992f-7ac1-8d0a-8beeb268c217" xlink:to="loc_oxy_EBPMasterTrustNameAxis_019e706c-992f-702d-baa9-fa67512ae603" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameDomain_019e706c-992f-702d-baa9-fa67512ae603_default" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_oxy_EBPMasterTrustNameAxis_019e706c-992f-702d-baa9-fa67512ae603" xlink:to="loc_oxy_EBPMasterTrustNameDomain_019e706c-992f-702d-baa9-fa67512ae603_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameDomain_019e706c-992f-74af-97a8-d3ec7e1979e5" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_oxy_EBPMasterTrustNameAxis_019e706c-992f-702d-baa9-fa67512ae603" xlink:to="loc_oxy_EBPMasterTrustNameDomain_019e706c-992f-74af-97a8-d3ec7e1979e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_DefinedContributionPlanMasterTrustMember_019e706c-992f-7b1a-9edd-e2a59679e44f" xlink:href="oxy-20260629.xsd#oxy_DefinedContributionPlanMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPMasterTrustNameDomain_019e706c-992f-74af-97a8-d3ec7e1979e5" xlink:to="loc_oxy_DefinedContributionPlanMasterTrustMember_019e706c-992f-7b1a-9edd-e2a59679e44f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_GuaranteedInvestmentContractsMasterTrustInvestmentAccountMember_019e706f-e615-730f-8746-bef5bbca3b80" xlink:href="oxy-20260629.xsd#oxy_GuaranteedInvestmentContractsMasterTrustInvestmentAccountMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPMasterTrustNameDomain_019e706c-992f-74af-97a8-d3ec7e1979e5" xlink:to="loc_oxy_GuaranteedInvestmentContractsMasterTrustInvestmentAccountMember_019e706f-e615-730f-8746-bef5bbca3b80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e706c-992f-732a-be92-56d2ae710343" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e706c-992f-7ac1-8d0a-8beeb268c217" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e706c-992f-732a-be92-56d2ae710343" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-732a-be92-56d2ae710343_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e706c-992f-732a-be92-56d2ae710343" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-732a-be92-56d2ae710343_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-7563-95a1-939cea17fd9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e706c-992f-732a-be92-56d2ae710343" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-7563-95a1-939cea17fd9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e706c-992f-7c3b-bb54-78ced98caf52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-7563-95a1-939cea17fd9d" xlink:to="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e706c-992f-7c3b-bb54-78ced98caf52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849f-1132-7fae-b3c4-a7b8d66df3b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-7563-95a1-939cea17fd9d" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849f-1132-7fae-b3c4-a7b8d66df3b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019e706c-992f-7936-8d3f-7409efaca1ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e706c-992f-7563-95a1-939cea17fd9d" xlink:to="loc_us-gaap_MutualFundMember_019e706c-992f-7936-8d3f-7409efaca1ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e706d-572f-73c1-bee1-4737548dc323" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e706d-572f-73c1-bee1-4737548dc323" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019e706c-992f-76c1-b500-c560593542d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019e706d-572f-73c1-bee1-4737548dc323" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019e706c-992f-76c1-b500-c560593542d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForInvestmentIncomeLossBeforeInvestmentExpense_019e706f-e615-7ec7-a946-d065bba11b50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForInvestmentIncomeLossBeforeInvestmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForInvestmentIncomeLossBeforeInvestmentExpense_019e706f-e615-7ec7-a946-d065bba11b50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment_019e706c-992f-7efc-8449-13b558e32eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment_019e706c-992f-7efc-8449-13b558e32eb7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForInvestmentExpense_019e706c-992f-7e73-88f8-505eaf3d95b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForInvestmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForInvestmentExpense_019e706c-992f-7e73-88f8-505eaf3d95b8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForInvestmentIncomeLossAfterInvestmentExpense_019e706c-992f-7fdd-be75-c404f1cc7990" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForInvestmentIncomeLossAfterInvestmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForInvestmentIncomeLossAfterInvestmentExpense_019e706c-992f-7fdd-be75-c404f1cc7990" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPChangeInNetAssetAvailableForBenefitTransferToPlan_019f03fb-eac2-7598-89f9-09f6fe991d3f" xlink:href="oxy-20260629.xsd#oxy_EBPChangeInNetAssetAvailableForBenefitTransferToPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_oxy_EBPChangeInNetAssetAvailableForBenefitTransferToPlan_019f03fb-eac2-7598-89f9-09f6fe991d3f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPChangeInNetAssetAvailableForBenefitTransferFromPlan_019f03fc-2310-7c37-a393-1294198a8009" xlink:href="oxy-20260629.xsd#oxy_EBPChangeInNetAssetAvailableForBenefitTransferFromPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_oxy_EBPChangeInNetAssetAvailableForBenefitTransferFromPlan_019f03fc-2310-7c37-a393-1294198a8009" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019e706c-992f-7874-a25a-dfdf9ad836bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e706c-992f-7d1c-84f7-fe2775c3b033" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019e706c-992f-7874-a25a-dfdf9ad836bc" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/PlanInterestinMasterTrustAccountsScheduleofFairValueMeasurementDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#PlanInterestinMasterTrustAccountsScheduleofFairValueMeasurementDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/PlanInterestinMasterTrustAccountsScheduleofFairValueMeasurementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6fd7-7515-7219-88a6-af43562b9415" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6fd7-7515-761e-b97b-f25deedd48b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6fd7-7515-7219-88a6-af43562b9415" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6fd7-7515-761e-b97b-f25deedd48b9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6fd7-7515-7784-b297-517a6ce4af20" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6fd7-7515-761e-b97b-f25deedd48b9" xlink:to="loc_dei_LegalEntityAxis_019e6fd7-7515-7784-b297-517a6ce4af20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6fd7-7515-7784-b297-517a6ce4af20_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6fd7-7515-7784-b297-517a6ce4af20" xlink:to="loc_dei_EntityDomain_019e6fd7-7515-7784-b297-517a6ce4af20_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6fd7-7515-7629-8055-5e3b44ebfecc" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6fd7-7515-7784-b297-517a6ce4af20" xlink:to="loc_dei_EntityDomain_019e6fd7-7515-7629-8055-5e3b44ebfecc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6fd7-bde0-7462-9ae0-b41b17720439" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6fd7-7515-7629-8055-5e3b44ebfecc" xlink:to="loc_oxy_EBP001Member_019e6fd7-bde0-7462-9ae0-b41b17720439" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e6fd7-7515-7180-bd26-2ce75c65420b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6fd7-7515-761e-b97b-f25deedd48b9" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e6fd7-7515-7180-bd26-2ce75c65420b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-7180-bd26-2ce75c65420b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e6fd7-7515-7180-bd26-2ce75c65420b" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-7180-bd26-2ce75c65420b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-73ed-817a-15f7b22650de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e6fd7-7515-7180-bd26-2ce75c65420b" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-73ed-817a-15f7b22650de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e6fd8-5942-79c0-8128-822df552ff52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-73ed-817a-15f7b22650de" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e6fd8-5942-79c0-8128-822df552ff52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019e6fd8-b5cc-7dbc-9b1a-286d7e05778d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-73ed-817a-15f7b22650de" xlink:to="loc_us-gaap_MutualFundMember_019e6fd8-b5cc-7dbc-9b1a-286d7e05778d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestmentsMember_019e6fd8-8881-7db8-9692-3edb891cfe69" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-73ed-817a-15f7b22650de" xlink:to="loc_us-gaap_ShortTermInvestmentsMember_019e6fd8-8881-7db8-9692-3edb891cfe69" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e6fd8-dd43-7b30-9426-c37e9ee7a9f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6fd7-7515-73ed-817a-15f7b22650de" xlink:to="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e6fd8-dd43-7b30-9426-c37e9ee7a9f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6fd9-df76-72f0-98c8-565f00d371ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6fd7-7515-761e-b97b-f25deedd48b9" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6fd9-df76-72f0-98c8-565f00d371ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6fd9-df76-72f0-98c8-565f00d371ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6fd9-df76-72f0-98c8-565f00d371ec" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6fd9-df76-72f0-98c8-565f00d371ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6fd9-df76-709a-8f73-fcff70b5114b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6fd9-df76-72f0-98c8-565f00d371ec" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6fd9-df76-709a-8f73-fcff70b5114b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel12And3Member_019e6fda-db78-7d35-82eb-1aab90ff1d4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel12And3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6fd9-df76-709a-8f73-fcff70b5114b" xlink:to="loc_us-gaap_FairValueInputsLevel12And3Member_019e6fda-db78-7d35-82eb-1aab90ff1d4d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019e6fd9-f43c-713e-9e4c-e02aa80225d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueInputsLevel12And3Member_019e6fda-db78-7d35-82eb-1aab90ff1d4d" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019e6fd9-f43c-713e-9e4c-e02aa80225d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_019e6fda-2d39-765b-896f-995f4a3c9fe4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6fd9-df76-709a-8f73-fcff70b5114b" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_019e6fda-2d39-765b-896f-995f4a3c9fe4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameAxis_019edb9a-52fa-7f32-96fd-65ce7e9de640" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustTable_019e6fd7-7515-761e-b97b-f25deedd48b9" xlink:to="loc_oxy_EBPMasterTrustNameAxis_019edb9a-52fa-7f32-96fd-65ce7e9de640" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameDomain_019edb9a-52fa-7f32-96fd-65ce7e9de640_default" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_oxy_EBPMasterTrustNameAxis_019edb9a-52fa-7f32-96fd-65ce7e9de640" xlink:to="loc_oxy_EBPMasterTrustNameDomain_019edb9a-52fa-7f32-96fd-65ce7e9de640_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPMasterTrustNameDomain_019edb9a-52fa-75d0-9d1e-b76107635969" xlink:href="oxy-20260629.xsd#oxy_EBPMasterTrustNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_oxy_EBPMasterTrustNameAxis_019edb9a-52fa-7f32-96fd-65ce7e9de640" xlink:to="loc_oxy_EBPMasterTrustNameDomain_019edb9a-52fa-75d0-9d1e-b76107635969" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_DefinedContributionPlanMasterTrustMember_019edb9a-a02c-7ecf-8784-af08377cac79" xlink:href="oxy-20260629.xsd#oxy_DefinedContributionPlanMasterTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oxy_EBPMasterTrustNameDomain_019edb9a-52fa-75d0-9d1e-b76107635969" xlink:to="loc_oxy_DefinedContributionPlanMasterTrustMember_019edb9a-a02c-7ecf-8784-af08377cac79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e6fd7-7515-7114-9678-6fda7c4ee5e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanMasterTrustLineItems_019e6fd7-7515-7219-88a6-af43562b9415" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValue_019e6fd7-7515-7114-9678-6fda7c4ee5e7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/RelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#RelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems_019e6599-8623-7f62-aca7-c5d5b15eae1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_019e6599-8623-7b6e-a48d-2c97b7420094" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems_019e6599-8623-7f62-aca7-c5d5b15eae1f" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_019e6599-8623-7b6e-a48d-2c97b7420094" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-70d1-bffb-e5592e20f420" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_019e6599-8623-7b6e-a48d-2c97b7420094" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-70d1-bffb-e5592e20f420" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-70d1-bffb-e5592e20f420_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-70d1-bffb-e5592e20f420" xlink:to="loc_dei_EntityDomain_019e6599-8623-70d1-bffb-e5592e20f420_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-738c-9382-1c46e1452f3f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-70d1-bffb-e5592e20f420" xlink:to="loc_dei_EntityDomain_019e6599-8623-738c-9382-1c46e1452f3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7b3a-aa75-a1b74ee82c21" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-738c-9382-1c46e1452f3f" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7b3a-aa75-a1b74ee82c21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPAdministrativeExpenses_019e6f91-70dc-7b0d-a47e-c5a148891de5" xlink:href="oxy-20260629.xsd#oxy_EBPAdministrativeExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsLineItems_019e6599-8623-7f62-aca7-c5d5b15eae1f" xlink:to="loc_oxy_EBPAdministrativeExpenses_019e6f91-70dc-7b0d-a47e-c5a148891de5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/RisksandUncertaintiesDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#RisksandUncertaintiesDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/RisksandUncertaintiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6f99-abc8-7180-b018-41d92daa8c75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpRiskAndUncertaintyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6f99-abc8-7d15-8e68-b515eca38fa0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpRiskAndUncertaintyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6f99-abc8-7180-b018-41d92daa8c75" xlink:to="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6f99-abc8-7d15-8e68-b515eca38fa0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6f99-abc8-7546-8277-30aa43e9c4cc" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6f99-abc8-7d15-8e68-b515eca38fa0" xlink:to="loc_dei_LegalEntityAxis_019e6f99-abc8-7546-8277-30aa43e9c4cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6f99-abc8-7546-8277-30aa43e9c4cc_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6f99-abc8-7546-8277-30aa43e9c4cc" xlink:to="loc_dei_EntityDomain_019e6f99-abc8-7546-8277-30aa43e9c4cc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6f99-abc8-7712-b902-470b579cec11" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6f99-abc8-7546-8277-30aa43e9c4cc" xlink:to="loc_dei_EntityDomain_019e6f99-abc8-7712-b902-470b579cec11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6f99-abc8-73c3-9776-2b3fe569a175" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6f99-abc8-7712-b902-470b579cec11" xlink:to="loc_oxy_EBP001Member_019e6f99-abc8-73c3-9776-2b3fe569a175" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019e6f9a-4170-70b8-9a00-af0d8c454699" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6f99-abc8-7d15-8e68-b515eca38fa0" xlink:to="loc_us-gaap_InvestmentTypeAxis_019e6f9a-4170-70b8-9a00-af0d8c454699" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e6f9a-4170-70b8-9a00-af0d8c454699_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e6f9a-4170-70b8-9a00-af0d8c454699" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e6f9a-4170-70b8-9a00-af0d8c454699_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019e6f9a-4170-74de-87bf-d26413f50262" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019e6f9a-4170-70b8-9a00-af0d8c454699" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019e6f9a-4170-74de-87bf-d26413f50262" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849f-61e1-7932-b1e1-471f9f4abc7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019e6f9a-4170-74de-87bf-d26413f50262" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e849f-61e1-7932-b1e1-471f9f4abc7a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019e8f5c-ed20-757a-bba6-ea6e7ecde0ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyTable_019e6f99-abc8-7d15-8e68-b515eca38fa0" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019e8f5c-ed20-757a-bba6-ea6e7ecde0ed" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019e8f5c-ed20-757a-bba6-ea6e7ecde0ed_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019e8f5c-ed20-757a-bba6-ea6e7ecde0ed" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019e8f5c-ed20-757a-bba6-ea6e7ecde0ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019e8f5c-ed20-715d-8772-c726a9d5302d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019e8f5c-ed20-757a-bba6-ea6e7ecde0ed" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019e8f5c-ed20-715d-8772-c726a9d5302d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019e8f5d-051f-7fdc-93f7-8e52cbc372dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019e8f5c-ed20-715d-8772-c726a9d5302d" xlink:to="loc_us-gaap_SubsequentEventMember_019e8f5d-051f-7fdc-93f7-8e52cbc372dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpRiskAndUncertaintyConcentrationOfInvestmentAtFairValueToTotalInvestmentsPercentage_019e6f99-abc8-743c-b542-24bd1310523d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpRiskAndUncertaintyConcentrationOfInvestmentAtFairValueToTotalInvestmentsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6f99-abc8-7180-b018-41d92daa8c75" xlink:to="loc_us-gaap-ebp_EbpRiskAndUncertaintyConcentrationOfInvestmentAtFairValueToTotalInvestmentsPercentage_019e6f99-abc8-743c-b542-24bd1310523d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPRiskAndUncertaintyAverageWTIPrice_019e6f99-abc8-77b9-8da6-c8a50be3ec30" xlink:href="oxy-20260629.xsd#oxy_EBPRiskAndUncertaintyAverageWTIPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyLineItems_019e6f99-abc8-7180-b018-41d92daa8c75" xlink:to="loc_oxy_EBPRiskAndUncertaintyAverageWTIPrice_019e6f99-abc8-77b9-8da6-c8a50be3ec30" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500ReconciliationofNetAssetsAvailableforBenefitDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#ReconciliationoftheFinancialStatementstotheForm5500ReconciliationofNetAssetsAvailableforBenefitDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500ReconciliationofNetAssetsAvailableforBenefitDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7114-bb15-4126c2da54b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-7f76-83d1-31f08d98ab7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7114-bb15-4126c2da54b8" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-7f76-83d1-31f08d98ab7c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-78b7-981a-ced561d8f9bf" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-7f76-83d1-31f08d98ab7c" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-78b7-981a-ced561d8f9bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-78b7-981a-ced561d8f9bf_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-78b7-981a-ced561d8f9bf" xlink:to="loc_dei_EntityDomain_019e6599-8623-78b7-981a-ced561d8f9bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-787a-bbba-e8ce2bcf69ce" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-78b7-981a-ced561d8f9bf" xlink:to="loc_dei_EntityDomain_019e6599-8623-787a-bbba-e8ce2bcf69ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7b6c-9542-e864efc1b881" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-787a-bbba-e8ce2bcf69ce" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7b6c-9542-e864efc1b881" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e662f-c58e-72ce-814c-691c4a5ab3d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7114-bb15-4126c2da54b8" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_019e662f-c58e-72ce-814c-691c4a5ab3d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500NetAssetAvailableForBenefitAllocationToWithdrawingParticipantNotYetPaid_019e6630-2d87-79da-997f-6395a543e96b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500NetAssetAvailableForBenefitAllocationToWithdrawingParticipantNotYetPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7114-bb15-4126c2da54b8" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500NetAssetAvailableForBenefitAllocationToWithdrawingParticipantNotYetPaid_019e6630-2d87-79da-997f-6395a543e96b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionNetAssetAvailableForBenefit_019e6630-4e99-78a5-b3f2-ccb07655644f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionNetAssetAvailableForBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7114-bb15-4126c2da54b8" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionNetAssetAvailableForBenefit_019e6630-4e99-78a5-b3f2-ccb07655644f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500ReconciliationofBenefitsPaidDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#ReconciliationoftheFinancialStatementstotheForm5500ReconciliationofBenefitsPaidDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ReconciliationoftheFinancialStatementstotheForm5500ReconciliationofBenefitsPaidDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7dc2-8d98-e5ed38d2c28e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-710a-a269-f44bf024a2d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7dc2-8d98-e5ed38d2c28e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-710a-a269-f44bf024a2d0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-75f7-ac08-47194643e9b2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500Table_019e6599-8623-710a-a269-f44bf024a2d0" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-75f7-ac08-47194643e9b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-75f7-ac08-47194643e9b2_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-75f7-ac08-47194643e9b2" xlink:to="loc_dei_EntityDomain_019e6599-8623-75f7-ac08-47194643e9b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7b96-846d-6769f6d90421" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-75f7-ac08-47194643e9b2" xlink:to="loc_dei_EntityDomain_019e6599-8623-7b96-846d-6769f6d90421" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7442-bfcf-1a946bcd3eff" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-7b96-846d-6769f6d90421" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7442-bfcf-1a946bcd3eff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019e6fa1-d158-7730-846e-f23d7584586c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7dc2-8d98-e5ed38d2c28e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019e6fa1-d158-7730-846e-f23d7584586c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500PaymentToParticipantDecreaseForAllocationToWithdrawingParticipantPaid_019e6fa0-dfd8-74e4-8a0f-a447e7871ddf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500PaymentToParticipantDecreaseForAllocationToWithdrawingParticipantPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7dc2-8d98-e5ed38d2c28e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500PaymentToParticipantDecreaseForAllocationToWithdrawingParticipantPaid_019e6fa0-dfd8-74e4-8a0f-a447e7871ddf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500PaymentToParticipantIncreaseForAllocationToWithdrawingParticipantNotYetPaid_019e6fa0-f872-7c3a-b561-6c26c09b6180" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500PaymentToParticipantIncreaseForAllocationToWithdrawingParticipantNotYetPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7dc2-8d98-e5ed38d2c28e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500PaymentToParticipantIncreaseForAllocationToWithdrawingParticipantNotYetPaid_019e6fa0-f872-7c3a-b561-6c26c09b6180" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionPaymentToParticipant_019e6fa0-c74f-7ddb-8d7d-ddabb4c4d91c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionPaymentToParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReconciliationToForm5500LineItems_019e6599-8623-7dc2-8d98-e5ed38d2c28e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanForm5500CaptionPaymentToParticipant_019e6fa0-c74f-7ddb-8d7d-ddabb4c4d91c" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7fdf-a4db-fb5125a27abe_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:to="loc_dei_EntityDomain_019e6599-8623-7fdf-a4db-fb5125a27abe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-76da-aa83-740ea255548e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:to="loc_dei_EntityDomain_019e6599-8623-76da-aa83-740ea255548e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7df8-a1a2-6c6570fc5f20" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-76da-aa83-740ea255548e" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7df8-a1a2-6c6570fc5f20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:to="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f03f1-d9a5-7715-a715-ac4936e20702_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:to="loc_srt_RangeMember_019f03f1-d9a5-7715-a715-ac4936e20702_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:to="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f03f1-fa46-7558-aeed-1abd21b604e9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:to="loc_srt_MinimumMember_019f03f1-fa46-7558-aeed-1abd21b604e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f03f2-0bae-7e1a-a071-3cdcc69ba34f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:to="loc_srt_MaximumMember_019f03f2-0bae-7e1a-a071-3cdcc69ba34f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIdentifierAxis_019e6599-8623-7a4d-81c2-ba0b0b7738ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:to="loc_us-gaap_InvestmentIdentifierAxis_019e6599-8623-7a4d-81c2-ba0b0b7738ab" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7e37-b57b-7e02583ce3af" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7e37-b57b-7e02583ce3af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-7fad-b495-d9fe679e7053" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-7fad-b495-d9fe679e7053" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue_019e6f07-1951-7338-a792-e0d28231779a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue_019e6f07-1951-7338-a792-e0d28231779a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanCost_019e6f07-f905-7e86-9bcd-42886f177c03" xlink:href="oxy-20260629.xsd#oxy_EBPAssetHeldForInvestmentParticipantLoanCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanCost_019e6f07-f905-7e86-9bcd-42886f177c03" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution_019e6f09-127a-73bd-8ddd-b1d0199c7c15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution_019e6f09-127a-73bd-8ddd-b1d0199c7c15" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustCurrentValue_019e6f17-4db4-7cf8-a23a-2be028d7f8cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustCurrentValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustCurrentValue_019e6f17-4db4-7cf8-a23a-2be028d7f8cb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment_019e6f18-dc31-7860-abcf-23be7c7bfcff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment_019e6f18-dc31-7860-abcf-23be7c7bfcff" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares_019f03f5-43b2-7502-abdb-ed5009f9ee8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares_019f03f5-43b2-7502-abdb-ed5009f9ee8a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanNumber_019f03f7-5293-7ec8-b85f-a27d241689ae" xlink:href="oxy-20260629.xsd#oxy_EBPAssetHeldForInvestmentParticipantLoanNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanNumber_019f03f7-5293-7ec8-b85f-a27d241689ae" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate_019f03f1-b39d-799e-8f14-7436dbcf30a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate_019f03f1-b39d-799e-8f14-7436dbcf30a1" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails_1" xlink:type="simple" xlink:href="oxy-20260629.xsd#ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails_1"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ScheduleHLine4iScheduleofAssetsHeldatEndofYearDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7fdf-a4db-fb5125a27abe_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:to="loc_dei_EntityDomain_019e6599-8623-7fdf-a4db-fb5125a27abe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-76da-aa83-740ea255548e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7fdf-a4db-fb5125a27abe" xlink:to="loc_dei_EntityDomain_019e6599-8623-76da-aa83-740ea255548e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-7df8-a1a2-6c6570fc5f20" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-76da-aa83-740ea255548e" xlink:to="loc_oxy_EBP001Member_019e6599-8623-7df8-a1a2-6c6570fc5f20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019e6599-8623-78df-a3a7-c32ad3883bf2" xlink:to="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f03f1-d9a5-7715-a715-ac4936e20702_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:to="loc_srt_RangeMember_019f03f1-d9a5-7715-a715-ac4936e20702_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f03f1-d9a5-7715-a715-ac4936e20702" xlink:to="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f03f1-fa46-7558-aeed-1abd21b604e9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:to="loc_srt_MinimumMember_019f03f1-fa46-7558-aeed-1abd21b604e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f03f2-0bae-7e1a-a071-3cdcc69ba34f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f03f1-d9a5-7f1d-8424-136823c7f4a4" xlink:to="loc_srt_MaximumMember_019f03f2-0bae-7e1a-a071-3cdcc69ba34f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7e37-b57b-7e02583ce3af" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7e37-b57b-7e02583ce3af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-7fad-b495-d9fe679e7053" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-7fad-b495-d9fe679e7053" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue_019e6f07-1951-7338-a792-e0d28231779a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue_019e6f07-1951-7338-a792-e0d28231779a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanCost_019e6f07-f905-7e86-9bcd-42886f177c03" xlink:href="oxy-20260629.xsd#oxy_EBPAssetHeldForInvestmentParticipantLoanCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanCost_019e6f07-f905-7e86-9bcd-42886f177c03" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution_019e6f09-127a-73bd-8ddd-b1d0199c7c15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentParticipantLoanAfterDeemedDistribution_019e6f09-127a-73bd-8ddd-b1d0199c7c15" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustCurrentValue_019e6f17-4db4-7cf8-a23a-2be028d7f8cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustCurrentValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPlanInterestInMasterTrustCurrentValue_019e6f17-4db4-7cf8-a23a-2be028d7f8cb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment_019e6f18-dc31-7860-abcf-23be7c7bfcff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment_019e6f18-dc31-7860-abcf-23be7c7bfcff" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares_019f03f5-43b2-7502-abdb-ed5009f9ee8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares_019f03f5-43b2-7502-abdb-ed5009f9ee8a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanNumber_019f03f7-5293-7ec8-b85f-a27d241689ae" xlink:href="oxy-20260629.xsd#oxy_EBPAssetHeldForInvestmentParticipantLoanNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_oxy_EBPAssetHeldForInvestmentParticipantLoanNumber_019f03f7-5293-7ec8-b85f-a27d241689ae" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate_019f03f1-b39d-799e-8f14-7436dbcf30a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019e6599-8623-7118-93ed-1bebc0e37fad" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate_019f03f1-b39d-799e-8f14-7436dbcf30a1" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ScheduleHLine4jScheduleofReportableTransactionsDetails" xlink:type="simple" xlink:href="oxy-20260629.xsd#ScheduleHLine4jScheduleofReportableTransactionsDetails"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ScheduleHLine4jScheduleofReportableTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7924-9441-159331eb776f_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:to="loc_dei_EntityDomain_019e6599-8623-7924-9441-159331eb776f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-749a-a368-8111f9a33992" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:to="loc_dei_EntityDomain_019e6599-8623-749a-a368-8111f9a33992" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-70b2-a33f-28f675f60844" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-749a-a368-8111f9a33992" xlink:to="loc_oxy_EBP001Member_019e6599-8623-70b2-a33f-28f675f60844" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIdentifierAxis_019e6599-8623-718a-a5c0-30be313b36ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:to="loc_us-gaap_InvestmentIdentifierAxis_019e6599-8623-718a-a5c0-30be313b36ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7155-a540-d477939dbde3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7155-a540-d477939dbde3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-791a-ab4e-e5b1bc92c04d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-791a-ab4e-e5b1bc92c04d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustPurchasePrice_019e6f22-0361-7cc4-8a08-ab2e0276240f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustPurchasePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustPurchasePrice_019e6f22-0361-7cc4-8a08-ab2e0276240f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice_019e6f22-4859-728c-9fac-1d2664299d39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice_019e6f22-4859-728c-9fac-1d2664299d39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost_019e6f22-bcfd-754d-bfb4-a0c188336fa9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost_019e6f22-bcfd-754d-bfb4-a0c188336fa9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCurrentValue_019e6f23-1b8f-779b-8b20-fef13b63b948" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCurrentValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCurrentValue_019e6f23-1b8f-779b-8b20-fef13b63b948" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://oxy.com/role/ScheduleHLine4jScheduleofReportableTransactionsDetails_1" xlink:type="simple" xlink:href="oxy-20260629.xsd#ScheduleHLine4jScheduleofReportableTransactionsDetails_1"/>
  <link:definitionLink xlink:role="http://oxy.com/role/ScheduleHLine4jScheduleofReportableTransactionsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionTable_019e6599-8623-7873-896f-8bd279e421e7" xlink:to="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-7924-9441-159331eb776f_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:to="loc_dei_EntityDomain_019e6599-8623-7924-9441-159331eb776f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e6599-8623-749a-a368-8111f9a33992" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e6599-8623-7924-9441-159331eb776f" xlink:to="loc_dei_EntityDomain_019e6599-8623-749a-a368-8111f9a33992" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_oxy_EBP001Member_019e6599-8623-70b2-a33f-28f675f60844" xlink:href="oxy-20260629.xsd#oxy_EBP001Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e6599-8623-749a-a368-8111f9a33992" xlink:to="loc_oxy_EBP001Member_019e6599-8623-70b2-a33f-28f675f60844" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7155-a540-d477939dbde3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e6599-8623-7155-a540-d477939dbde3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-791a-ab4e-e5b1bc92c04d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019e6599-8623-791a-ab4e-e5b1bc92c04d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustPurchasePrice_019e6f22-0361-7cc4-8a08-ab2e0276240f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustPurchasePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustPurchasePrice_019e6f22-0361-7cc4-8a08-ab2e0276240f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice_019e6f22-4859-728c-9fac-1d2664299d39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice_019e6f22-4859-728c-9fac-1d2664299d39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost_019e6f22-bcfd-754d-bfb4-a0c188336fa9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost_019e6f22-bcfd-754d-bfb4-a0c188336fa9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCurrentValue_019e6f23-1b8f-779b-8b20-fef13b63b948" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCurrentValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfReportableTransactionLineItems_019e6599-8623-79b3-a108-b3df2a6e0d1e" xlink:to="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCurrentValue_019e6f23-1b8f-779b-8b20-fef13b63b948" xlink:type="arc" order="5"/>
  </link:definitionLink>
</link:linkbase>
